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VETERINARY MEDICINE SERIES 
No. 4 



SWINE DISEASES 



./• .^' BY 




AfT. KINSLEY, M. Sc, D. V. S. 



ILLUSTRATED 



Chicago 
AMERICAN JOURNAL OF VETERINARY MEDICINE 

1914 



Copyright 1914 

By 
D. M. Campbell 



DEC 26 1914 

CU3911H 



^^ 



^^V 



PREFACE 



The experience of the writer in teaching, and 
in the manufacture and distribution of anti-hog 
cholera serum, no less than in practice, has 
forcibly impressed upon him the need of the 
veterinary profession for more general knowl- 
edge of the diseases of swine. 

They are not few w^ho maintain that vet- 
erinary practice in the future will be concerned 
largely with the food-producing animals. The 
automobile has already supplanted most of the 
fancy driving horses; the auto-truck does much 
that would otherwise be accomplished by 
horses; and predictions are rife that the gaso- 
lene tractor will soon be made practicable for 
work on small farms. All things considered it 
seems probable that the equine population of 
the country is destined to increase but slowly if 
at all. The keeping of pet animals, including 
dogs and cats, is being looked upon more and 
more as an insanitary practice, while the farm 
dog and the roaming cur are becoming more 
and more the object of antagonistic legislation. 
Contrasted with the foregoing, the increasing 
price of meat food products makes it seem de- 
sirable that veterinarians in general better equip 
themselves for the treatment of the ailments of 
food producing animals and thus quahfy them- 
selves to render greater service to the public in 



a line of practice that is not likely to be affected 
by progress and invention. 

It is the aim of this work to supply this in- 
formation in a compact, readily assimilated 
form for both students and practitioners. Ac- 
knowledgement must be made to Dr. D. M. 
Campbell, editor of the American Journal of 
Veterinary Medicine for the illustrations 
used herein, and he wishes me to, in turn, 
acknowledge his indebtedness to Dr. L. Enos 
Day, in charge of the Branch Pathological 
Laboratory of the Bureau of Animal Industry 
of Chicago, and his assistant Dr. G. Tinsley 
Creech, for permission to photograph a number 
of specimens in the very excellent museimi 
maintained in connection with their laboratory. 
And also indebtedness to the American 
Serum Company of Kansas City for photographs 
of their plant used in illustrating the manu- 
facture of anti-hog cholera serum. 

A. T. Kinsley. 

Kansas City, December 1914. 



CONTENTS 



SECTION I. PAGE I 

The Digestive System 9 

Ldps; Malformations — Cheilitis — Tumors. Tongue; \ 

Glossitis — Tumors — Parasites. Mouth; Stomatitis — Scur- I 

vy — Parotiditis — Tonsillitis. Pharynx; Pharyngitis — ' 

Pharyngeal Paralysis — Tumors. Esophagus; Malforma- j 

tions — Stenosis '— Dilatation — Perforation — Esophagi tis i 

— Tumors. Stomach; Malformations — Foreign Bodies — I 

Emesis — Anemia — Hematamesis — Peptic Ulcers — Hyper- i 

emia — Gastritis — Dilatation — Tumors — Parasites. Intes- ] 

tines; Malformations — Entorrhagia — Obstruction — Dila- \ 

tations — Emphysema — Enteritis — Toxic Gastritis, Gastro- ' 

enteritis, Enteritis — Scours in Sucklings — Parasites — •! 

Tumors. Liver; Malformations — Foreign Bodies — Rup- j 

ture — Icterus — Cloudy Swelling — Fatty Changes — Amy- i 

loid Changes — Glycogenic Infiltration — Cholelithiasis — I 

Hyperemia — Hepatitis — Tumors — Parasites. Pancreas; \ 

Peritoneum; Injuries — Ascites — Peritonitis — Tumors — j 

Parasites. ^ 

SECTION II. i 

The Respiratory System 75 ■ 

Nose; Epistaxis — Rhinitis — Infectious Nasal Catarrh — '. 

Tumors. Larynx; Laryngitis — Tumors. Trachea; Mai- I 

formations — Stenosis — Tracheitis — Tumors. Bronchial i 
Tubes; Stenosis — Bronchitis — Verminous Bronchitis 

and P^neumonia. Lungs; Atelectasis — Emphysema — \ 

Edema — Hemorrhage — Pneumonia — Tumors — Parasites. i 

Pleura; Hydrothorax — Hemothorax — Pneumothorax — ! 

Pleurisy — Tumors. \ 

SECTION III. ' 

The Uro-Genital System 99 \ 

Kidneys; Malformations — Hydronephrosis — Hemor- .. ' 
rhage — Fatty Changes — Calculi — Congestion — Nephritis 
— Py elonephri tis — Albuminuria — Uremi a — Tumors — Par- ! 
asites. Ureters; Malformations. Bladder; Malforma- I 
tions — Hematuria — Dilatation— Calculi — Cystitis — Tum- 
ors. Urethra; Stricture — Urethritis. Prostate-Gland: I 
Cowper's Glands: Testicles; Orchitis and Epididymitis — • ; 
Tumors. Sequels to Castration; Hemorrhage — Infection — | 
Botryomycosis — Actinomycosis — Parasites — Scrotal Her- i 
nia. Penis: Ovary; Malformations^ — Hemorrhage — Ooph- ■ 
oritis — Cysts — Tumors. Fallopian Tubes: Uterus; Mai- ; 
formations — In j urics — Hemorrhage — M etritis — Tumors. | 
Vagina: Vulva: Mammary Glands; Mammitis — '\ 
Botryomycotic Mammitis — Actinomycotic Mammitis — 
Tuberculous Mammitis — Tumors. ] 

5 'i 



CONTENTS— Continued 



SECTION IV. 
Organs of Locomotion 135 

Sore Feet — Fatty Degeneration — Muscular Rheumatism 
— Articular Rheumatism — Rachitis — Osteomalatia — Puru- 
lent Osteomyelitis — Trichinosis — Cysticercosis (measles) 
— Sarcosporidiosis — Tumors. 

SECTION V. 

The Skin 149 

Erythema — Sunburning — Freezing — Hemorrhage — Urti- 
caria — Eczema — Dermatitis Granulosa — Necrobacillosis — 
Actin omy cosis — Tumors — Parasites . 

SECTION VI. 
Circulatory Organs 159 

Heart; Pericarditis — Hemorrhage — Fatty Changes — En- 
docarditis — Tumors — Parasites. Blood Vessels: Blood; 
Anemia — Leukemia. Spleen; Necrosis — Hyperthrophy 
— Sarcomatosis. 

SECTION VII. 

The Nervous System : 163 

M alf ormations — Delirium — Viciousness — Sunstroke — 
Heat Stroke — Lightning Stroke — Epilepsy — Dentition 
Eclampsia — Chorea— Cerebral Hyperemia — Parasites. 

SECTION VIII. 
Infectious Diseases 169 

Hog Cholera; History — ^Extent — Etiology — Sources of 
Infection — Manner of Infection — Susceptibility — Chan- 
nels of Infection — Period of Incubation — Lesions — Symp- 
tons — Diagnosis — Prognosis — Treatment — Preventative 
Treatment — Anti-Hog Cholera Serum — Manufacture and 
Use. Swine Plague: Necrobacillosis; Necrotic Stomati- 
tis — Necrotic Enteritis — Necrotic Rhinitis — Necrotic 
Pneumonia — Necrotic Hepatitis — Necrosis of the Spleen — 
Vaginal, Vulvar and Preputial Necrobacillosis — Necro- 
bacillosis of the Skin — Other Forms of Necrobacillosis. 
Tuberculosis: Pyemic Arthritis; Spasms of the Diaphragm: 
Rabies; Foot and Mouth Disease. 



ILLUSTRATIONS 



FIGURE PAGE 

1. Glossitis 11 

2. Ascaris Suum 48 

3. Gigantorhynchus Hirudinaceus 52 

4. Adeno-Sarcoma of the Kidney Ill 

5. Actinomycosis 121 

6. Scirrhous Cord due to Botryomycotic Infection 122 

7. Infection of the Udder 131 

8. Cysticercosis (Pork Measles) 145 

9. Pedunculated Fibroma 146 

10. Elephantiasis 152 

11. Mucous Membrane of the Bladder 177 

12. Mucous Membrane of the Intestine 179 

13. Hearts 181 

14. Early Stages of Hog Cholera 183 

15. Acute Hog Cholera, Advanced Stage 185 

16. Heart Showing Hemorrhages due to Hog Cholera 187 

17. Kidneys 188 

18. Lymph Nodes 189 

19. Virus Bleeding Room 194 

20. Hyperimmunizing Room 196 

21. Serum Centrifuging Room 200 

22. Sterihzing Room 201 

23. Cholera-Immune Hogs 203 

24. Necrobacillosis 212 

25. Fat Necrosis 215 

26. Tuberculosis of the Tongue 221 

27. Tuberculosis of the Skin 222 

28. Tuberculosis of the Pleura 225 

7 



COLOR PLATES 



PLATE 1 0pp. p. 182 

Fig. 1. Skin Lesions of Hog Cholera. 
Fig. 2. Intestinal Lesions of Hog Cholera. 

PLATE II 0pp. p. 198 

Fig. 1. Thrombosis of the Liver. 

Fig. 2. Pulmonary Lesions of Hog Cholera. 

PLATE III 0pp. p. 218 

Fig. 1. Hepatic Lesions of Tuberculosis. 
Fig. 2. Bone Lesions of Tuberculosis. 

PLATE IV 0pp. p. 224 

Fig. 1. Splenic Lesions of Tuberculosis. 
Fig. 2. Pulmonary Lesions of Tuberculosis. 



SECTION I 
THE DIGESTIVE SYSTEM 

The Mouth and its Associated Parts 

THE mouth of swine is prone to injuries and infection 
because they are Ukely to ingest foods in various 
states of refinement, and not infrequently they 
consume foreign bodies that may produce such injuries 
as contusions and lacerations. The comfort and health 
of swine are not always considered by the feeder, who may 
thoughtlessly give foods sufficiently hot or cold to produce 
damage to the buccal mucous membrane. Injuries to 
this membrane are predisposed to infection that may 
produce pathologic conditions varying from simple 
inflammation to suppuration or even necrosis. 

LIPS 

Malformations 

Malformations of the lips of swine are not rare, the 
most frequent malformation being the condition popularly 
termed **hair lip" (schistosis labii). This condition is 
rarely observed in mature swine because the defect 
renders nursing extremely difficult and frequently im- 
possible; such pigs, therefore, die before they have passed 
the nursing stage. Schistosis labii, when not associated 
with other developmental errors, is usually easily relieved 
by operation. 

Cheilitis 

The lips are also subject to injuries inflicted by 
rough foods or by foreign bodies in the food. Wounds, 
too, may be inflicted by dogs. Because of their location, 
lip wounds are predisposed to infection. Inflammatory 
processes of the lips are usually confined to the mucous 
surface. 



.10 SWINE DISEASES 

Catarrhal cheilitis is of rather common occurrence, 
particularly in small pigs, and may be either acute or 
chronic. This condition is usually caused by improper 
food or undue exposure to very dry atmosphere. The 
lesions of the acute type consist of small crevices which 
in extreme cases may bleed freely. In the chronic type 
the cracks and crevices become more extensive and the 
surrounding tissues are infiltrated with varying quantities 
of newly formed fibrous tissue. Catarrhal cheilitis, either 
acute or chronic, is not a serious condition and is usually 
corrected when the cause is removed. 

Suppurative cheilitis is occasionally observed. It is 
usually the result of infection of the subsurface labial 
tissues with pyogenic bacteria. The usual form of this 
type of cheilitis is circumscribed, and the lesions are 
similar to the lesions observed in the usual abscess 
formation. This condition is relieved by operation. 

Diphtheritic cheilitis is very prevalent in some sections 
of the United States, particularly in young pigs. The 
usual causative agent is the Bacillus necrophorus. This 
microorganism produces a variety of lesions and is of so 
great economic importance that all of the disease pro- 
cesses resulting from it will be discussed under the topic, 
"Necrobacillosis," in. Section VIII. (See p. 213.) 

Vesicular cheilitis has been reported as occurring in 
suckling pigs. This condition is probably caused by a 
yeast, the oidium albicans. The lesions of vesicular 
cheilitis are practically confined to the mucous surfaces 
of the lips. The mucous membrane is tumefied and 
scarlet red in color, and in the beginning and later small, 
sharply circumscribed vesicles appear and the mucosa 
becomes white, due to the accumulated desquamated 
epithelium and mucus. The vesicles rupture and the 
vesicular membrane may slough, leaving a denuded 
surface, or the vesicular membrane may collapse after 
the discharge of its content and appear as a small, white 
mass upon the mucous membrane. This condition is 
usually not serious, although it may cause considerable 



THE DIGESTIVE SYSTEM 



11 



inconvenience in sucking. It is usually relieved by the 
topical application of properly selected antiseptics. 

Tumors 

Labial tumors are not of common occurrence in 
swine, although fibroma, myxoma, and epithelioma have 
been observed. 

TONGUE 

The tongue is also subject to injuries of various 
types. Tongue injuries may be inflicted by improper 
food, by foreign bodies in the food, or by sharp, irregular 
teeth. 




Fig. 1.— GI.OSSITIS. 
This tongue was taken from an apparently normal hog. It contained 
twenty-four polished nails lodged in one place. 

Glossitis 

Inflammatory disturbances of the tongue may involve 
the mucous membrane only or the submucous muscular 
portion of the tongue. The inflammations of the lingual 
mucous membrane are practically identical with those of 
the Hps and will not be given further consideration. 
Inflammation of the lingual musculature is usually the 
sequel of an injury which had provided an avenue of 
entrance for infection. Inflammation of the substructures 
of the tongue may be acute or chronic, diffuse or cir- 



12 SWINE DISEASES 

« 

cumscribed, nonsuppurative or suppurative. Diffuse 
nonsuppurative subsurface glossitis is usually acute and is 
the result of infection with streptococci or some septic 
microorganism. The lesions in this type of glossitis 
consist of a diffuse, extensive tumefaction of the tongue, 
which on section evidences enlargement of the blood 
vessels and abundant accumulations of pus, or other 
inflammatory products, between the muscle bundles, 
while the muscle tissue will have a parboiled appearance. 
Acute circumscribed subsurface suppurative glossitis par- 
takes of the nature of an abscess. Chronic glossitis is 
most frequently diffuse and is exemplified in those cases 
of diffuse lingual actinomycosis. The lesions consist 
primarily of an excessive quantity of fibrous tissue which 
msiy contract unequally in different portions of the 
tongue, thus producing an irregularity of the surface of 
the organ. Portions of the tongue in which excessive 
quantities of fibrous tissues are developed become dense 
and hard, and cut with considerable resistance. 

Tumors 

Lingual tumors ^re relatively uncommon, but retention 
or obstruction cysts have been observed. 

Parasites 

Parasitic invasion of the tongue is not uncommon. 
The cystic form of the Taenia solium, that is, the 
Cysticercus cellulosse, frequently occurs in the muscular 
portion of the tongue. The cystic form of the Tri- 
chinella has also been observed in lingual muscles, while 
psorosperms occasionally inhabit the muscle of the tongue. 

MOUTH 

The mucous membrane of the mouth, other than 
that mentioned in relation to the lips and tongue, is 
subject to injuries of a similar origin and nature and 
will not be further discussed here. 



THE DIGESTIVE SYSTEM 13 

Stomatitis 

Catarrhal inflammation of the buccal mucous mem- 
brane is relatively common and may be local or general, 
acute or chronic. Acute catarrhal stomatitis is usually 
caused by the ingestion of improper food, although it 
may be associated with some general infective disease or 
be the result of injury. The practice of catching swine 
by means of a rope or wire over the upper jaw is very 
likely to produce injury to the buccal mucous membrane. 
The affected mucous membrane is in the beginning 
tumefied and increased in redness, and later the surface 
becomes coated by the accumulation of desquamated 
epithelium and mucous. Gradually this surface coating 
loosens and sloughs as the inflammation diminishes in 
intensity. The affected animals refuse to eat, or eat 
sparingly, and usually select soft foods. Although they 
may attempt to chew hard substances, as a rule they 
drop them quickly to the ground. Salivation is always 
present, and in extreme cases an offensive odor may be 
detected. 

The treatment consists of cleansing the affected parts 
with antiseptics and applying an astringent, such as 
myrrh. The affected animals should be given soft 
foods, and a good supply of clean, cool water. 

Chronic catarrhal stomatitis is caused by the continuous 
or prolonged action of some relatively mild irritant. 
This condition is associated with fibrous proliferation 
in the submucosa which in the early stages of the disease 
results in tumefaction of the mucosa. Later the newly 
formed fibrous tissue contracts, producing an irregular 
surface. There is also a gradual atrophy of the mucosa 
and occasionally the cicatrized fibrous tissue obstructs 
mucous gland ducts, thereby causing small retention 
cysts. 

Chronic catarrhal stomatitis is manifested by con- 
tinuous limited salivation and champing of the jaws. 
The treatment depends largely upon the progress of the 
disease. In all cases the cause should be determined 



14 SWINE DISEASES 

and removed. Soft foods should be given, and mild 
astringent antiseptic washes may be used. 

Phlegmonous stomatitis is relatively common in swine. 
It is usually caused by a streptococcic infection of the 
submucosa. The condition is usually general, the 
affected mucosa is intensely swollen and in the beginning 
is scarlet red in color, later assuming a purplish hue, and 
finally a dull gray color due to the accumulation of 
desquamated epithelium, mucous, and pus. Patches of 
mucous membrane may become necrotic and slough, 
leaving a red surface from which blood escapes freely. 
The tumefaction may be so intense that the mouth 
cavity becomes noticeably diminished, and the cheek 
mucous membrane may be forced between the teeth 
and lacerated during mastication. 

The affected animals refuse to eat, and although they 
frequent the drinking trough, they will actually drink 
very little. There will be a frothy, ill-smelling discharge 
from the mouth. There may be a rise of from one to 
three degrees Fahrenheit in temperature. The treatment 
consists of mouth washes of antiseptics, frequently 
applied. 

Vesicular ulcerative stomatitis is caused by the same 
agencies and presents lesions similar to vesicular cheilitis, 
and will not be further discussed. 

Diphtheritic stomatitis is not uncommon, particularly 
in suckling pigs. The further discussion of this condition 
will be found under the topic, "Necrobacillosis," in 
Section VIII. (See p. 216) 

Symptoms. — As above indicated, the symptoms of 
stomatitis of the various types vary only in intensity. 
There is more or less of salivation and drooling, champing 
of the jaws, and evidence of difficulty in mastication. On 
inspection the lesions will be evident, which are usually 
sufficient upon which to base a diagnosis. 

Treatment. — The treatment also will vary with the 
type of inflammation. In all instances the cause should 
be removed, and in the infectious types there should be 
topical application of some suitable antiseptic. 



THE DIGESTIVE SYSTEM 15 

Scurvy 

This is a disease manifested by ulceration and hemor- 
rhage of the gums, unthriftiness, and debility. It is of 
rather common occurrence in young pigs. 

Etiology. — There appears to be no specific exciting 
cause of this condition. However, it usually occurs in 
pigs that are improperly fed, kept in unsanitary quarters, 
or those produced from continued inbreeding. 

Lesions. — Scurvy is characterized by progressive 
ulceration of the gums. These ulcers are irregular, 
ragged, and bleed almost constantly. Petechial hemor- 
rhages may be found in the skin, and in the mucous 
and serous membranes. The liver and kidneys may 
show fatty changes. The spleen and lymph nodes are 
enlarged. 

Symptoms. — Progressive emaciation, dullness, dimin- 
ished appetite, increased thirst, and a dislike to move 
characterize scurvy. On inspection, the gum ulcerations 
will be observed, and there may also be cutaneous hemor- 
rhages visible. The disease is rather serious unless the 
cases are observed early. 

Parotitis — Parotiditis 

Parotitis is rare in swine. In The American Veterinary 
Review (Vol. 43, p. 298), Kaupp reported three fatal 
cases. It appears from the report that two dogs also 
contracted the disease. This condition is usually not 
serious, and when the conditions associated with it are 
relieved the lesions rapidly disappear. 

Tonsillitis 

The tonsillar tissue of swine is prone to either acute 
or chronic inflammation. Acute tonsillitis is closely 
associated with acute pharyngitis, and the cause is 
probably most frequently infectious in character. The 
tonsillar tissue becomes tumefied and projects above the 
surface, while the buccal mucous membrane is hot and 
red. The affected animals are indisposed and dull, and 



16 SWINE DISEASES 

have a tendency to extend the head and elevate the 
snout. There is usually a rise of temperature. Deglu- 
tition is difficult and may be associated with gagging 
and sometimes with vomition. There may be spasmodic 
coughing. 

The treatment consists, in the mild cases, in applying 
soothing astringents; in the more severe cases, tincture 
of iron chlorid may be used. Laxatives should be given 
to keep the bowels in an active state, and the animals 
should be placed in clean, well-ventilated quarters, and 
given liquid and easily digested foods. 

Chronic tonsillitis is less common than the acute 
form. It is characterized by distention of the tonsillar 
tissue by accumulated desiccated pus or even calcareous 
masses in the tonsillar crypts. 

PHARYNX 

The pharynx, like the mouth, is subject to trauma- 
tisms and infection. 

Pharyngitis 

Catarrhal 'pharyngitis is the most common type of 
inflammation, and may be either acute or chronic. The 
usual cause of the disease is improper food or undue 
exposure, although it may be caused by infection. 

The mucous membrane of the pharynx affected with 
acute catarrh is in the beginning dry and scarlet red, 
later becoming tumefied and coated with epithelium 
and mucous, which occasionally desquamates, leaving 
denuded areas. 

If the causative agent persists the condition becomes 
chronic. The chronic condition is evidenced by fibrous 
proliferation in the submucosa resulting, first, in a 
tumefaction, and then in protrusion of the pharyngeal 
mucosa, which may, by contraction of the newly formed 
fibrous tissues, result in a corrugation of the mucous 
membrane, or the newly formed fibrous tissues may be 
so extensive that the pharyngeal mucosa becomes uni- 



THE DIGESTIVE SYSTEM 17 

• 
formly tumefied, dense and hard. In either case the 
epitheHum of the mucous membrane becomes atrophied, 
leaving only a thin covering, usually of a squamous 
type of epithelium. 

Phlegmonous pharyngitis is not infrequently associated 
with phlegmonous stomatitis, although it may occur 
independently. Streptococci are the usual cause of 
phlegmonous pharyngitis, and the lesions are practically 
identical with those of phlegmonous stomatitis. 

Diphtheritic pharyngitis is not rare in swine. It is 
the result of the Bacillus necrophorus, and practically 
the same lesions are observed as in necrobacillosis. 

Paralysis 

Paralysis of the pharynx is a condition resulting 
from disturbances of the controlling pharyngeal nerves 
or of the muscles of the pharynx. This condition is 
usually associated with rabies, although it has been 
observed independent of that disease and probably 
resulted from the influences of some substance upon the 
deglutition centers of the medulla. 

Tumors 

Pharyngeal tumors in swine are not very common. 
Occasionally polypoid fibromas are observed, but they 
are rare. Of the malignant tumors the epitheliomas 
are most often met with; however, these are rare. 
Adenomas and carcinomas also have been observed, but 
infrequently. 

ESOPHAGUS 

Malformations 

Malformations of the esophagus are rather rare. 
The canal may end abruptly at the lower end of the 
upper third, beginning lower down, and continue to the 
stomach, or the esophagus may form a union with the 
trachea. In rare instances fistulous openings have been 
observed in the cervical region. 



18 SWINE DISEASES 

Stenosis 

Stenosis, or narrowing of the esophagus, is not infre- 
quent. This condition occurs most frequently at the 
pharyngo-esophageal junction or at the cardiac termina- 
tion, the cause being either extrinsic or intrinsic. 

Etiology. — ^Among extrinsic causes may be pressure 
from enlarged thyroids, tumors, aneurysms, or abscesses. 
Foreign bodies, too, often produce partial obstructions 
of the esophagus, thus causing a temporary stenosis. 
The intrinsic causes are most frequently due to scars 
or scar tissues that have formed as a result of injuries 
or of diseased processes of the esophageal tissues. 
Hyperplasia of the esophageal muscle, also, may pro- 
duce stenosis. 

Lesions. — The usual anatomical changes observed 
in esophageal stenosis consist of cicatrized fibrous tissues. 
The extent of the trouble varies, but as a rule it involves 
only a small portion of the esophagus. The stenosis 
may form a regular or irregular diminished lumen. 

Symptoms. — The symptoms evidenced in esophageal 
stenosis consist of difficult deglutition and sometimes 
dilatation (which see), succeeded by the formation of 
jabot, which may be observed in animals thin in flesh. 

Treatment. — Surgical interference, which may or 
may not be successful, depending upon the extent of the 
lesions and the age of the animal involved, is the only 
treatment for esophageal stenosis. 

Dilatation 

Esophageal dilatation is less frequently met with 
than stenosis, particularly in swine. 

Etiology. — Obstruction and stenosis of the esophagus 
are primary causes of esophageal dilatation, but it may 
be the result of traction from without. 

Lesions. — Dilatation usually affects the entire circum- 
ference of the esophagus, although in some instances the 
dilatation may be lateral and form a true diverticulum. 
In the dilated portion, the esophageal walls are usually 



THE DIGESTIVE SYSTEM 19 

attenuated, and, in rare instances, they may become so 
weak that they are easily ruptured. 

Symptoms. — The usual symptoms evidenced in an 
animal afflicted with esophageal dilatation consist of a 
gradually developing tumefaction or enlargement in 
the cervical region while the animal is eating, due to the 
accumulation of the food in the dilated portion of the 
esophagus. The enlargement gradually subsides after 
eating, until no enlargement is observed. 

Treatment. — The treatment of esophageal dilatation 
is of little avail, and is primarily confined to surgical 
interference. 

Perforation 

Esophageal perforation is not very common in swine. 

Etiology. — It may be the result of erosion due to 
disease processes, such as actinomycosis, tuberculosis, or 
necrobacillosis, resulting in a complete destruction of 
portions of the esophageal w^alls and thus permitting the 
contents of the esophagus to infiltrate into the surround- 
ing structures. 

Perforation msiy also result from injury due to some 
foreign body that has been ingested and lodged in the 
esophagus. Weston reported the case, in The American 
Veterinary Review (Vol. 40, p. 658), of a hog that had 
swallowed a piece of sharp tin, which had perforated the 
thoracic portion of the esophagus. A sinus was formed 
in the adjacent lung, in which a small mass of food had 
accumulated. 

Lesions. ^ — The lesions resulting from perforation of 
the esophagus are quite variable and consist not only of 
the destruction of the esophageal walls, but also of 
tissue changes induced by the escape of food from the 
esophagus in the surrounding tissues. In some instances 
the primary lesions consist of an inflammatory edema, 
while in other instances the primary lesions are tuber- 
culous, actinomycotic, or necrobacillary . 

Symptoms. — The symptoms resulting from eso- 
phageal perforation vary according to the secondary 



20 SWINE DISEASES 

lesions evolved. There may or may not be tumefaction 
of the tissues adjacent to the perforation. In all cases, 
there will be more or less difficulty in deglutition, and in 
extreme cases there will be aphagia. 

Treatment. — The treatment of esophageal perfora- 
tion depends upon removing the cause and healing the 
injuries, combined with proper diet. 

Esophagitis 

Esophagitis in hogs is not very common. It may be 
the result of the injury from foreign bodies, exposure, or 
infection. 

Catarrhal esophagitis is perhaps the most frequent 
type of inflammation and may be local or general. The 
usual lesions evidenced in the acute type consist of con- 
gestion, infiltration, and tumefaction of the mucous 
membrane, associated with desquamation of the epi- 
thelium. Ulceration may occur. The chronic type is 
characterized by an excessive development of fibrous 
tissue in the submucosa, and causes the mucous mem- 
brane to be thrown into folds. Chronic esophagitis is 
occasionally observed in hogs that are fed exclusively 
on distillery slops. 

Croupous esophagitis is usually the result of an invasion 
of Streptococci, although this condition may be associated 
with hog cholera or pneumonia. The disease is charac- 
terized by the accumulation upon the mucous membrane 
of a yellowish or brownish coagulated exudate. 

Phlegmonous esophagitis is usually observed as a 
sequel of perforation, or the escape of pus into the sub- 
mucosa from abscesses. This condition is sometimes 
associated with phlegmonous pharyngitis. The accumu- 
lated pus or other inflammatory exudate is frequently 
so extensive that the lumen of the esophagus is entirely 
closed. 

Tumors 

Tumors of the esophagus are relatively rare. Polypoid 
fibromas have been observed, and more rarely myxomas 



TPIE DIGESTIVE SYSTEM 21 

and myomas. Malignant tumors of the esophagus are 
quite rare, and when they do occur they are secondary. 

STOMACH 

Malformations 

Malformations of the stomach are comparatively 
rare in hogs. The stomach may be abnormally small 
and sometimes there is a constriction in the middle line 
producing the so-called hour-glass stomach. 

Foreign Bodies 

Foreign bodies in the stomach are comparatively 
frequent because hogs have a marked tendency to swallow 
objects of various kinds. The following was found in 
one hog's stomach: 

40 nails. 1 No. 10 shotgun shell. 

15 staples. 2 buggy-top tacks. 

4 screws. 5 pieces of iron. 

4 nuts. 1 metal picture frame. 

9 pebbles. 6 pieces of zinc. 

1 snap. 8 pieces of wire. 

2 bolts. 1 piece of glass. 
1 brass pin. 1 piece of brass, 
1 piece porcelain. 

Hair balls (trichobezoars) are occasionally observed 
in swine. 

The damage due to foreign bodies in the stomach of 
swine depends upon their nature. Some sharp objects 
inflict wounds of various dimensions, and in some in- 
stances perforation occurs, succeeded by peritonitis. 

Lesions. — The lesions will vary with the nature of 
the foreign objects ; in some cases there is only a catarrhal 
condition, while in other instances there may be laceration 
or even perforation of the stomach walls. 

Symptoms. — Evidences of gastric foreign bodies are 
by no means sufficiently distinct to differentiate this 
condition from various other gastric disorders. 

Treatment. ^ — Little is available in the form of 
treatment of swine that have ingested foreign bodies. 
Small objects may be expelled by vomition excited by 



22 SWINE DISEASES 

emetics, or may be removed by gastric lavage. Objects 
imbedded in the gastric walls can be removed only by 
surgical interference, but gastric surgery in swine is not 
well developed at this time. 

Vomition (Emesis) 

Vomition is rather common in swine and is the result 
of stimulation of the vomition center, which is located 
in the medulla. This stimulation may be direct from 
irritation in the nerve center, but more frequently it is 
indirect from irritation of some portion of the gastro- 
intestinal tract. Vomition is therefore a symptom of a 
variety of disease conditions. It may be caused by 
engorgement of the stomach, nature having provided 
this method of relieving an overloaded stomach. In- 
testinal obstruction is another frequent cause of vomition 
in swine, as is also irritation of the mucosa of the eso- 
phagus, intestine, and more especially the stomach. 
Thus hog cholera is frequently evidenced by vomition. 
Gastric parasites not infrequently cause sufficient irri- 
tation to produce violent vomition, particularly in small 
pigs, while chemical irritants acting upon the digestive 
mucosa may produce vomition. 

Swine as a rule vomit easily. The affected animals 
become uneasy and restless. They extend the head and 
depress the nose, the esophageal muscles are relaxed, 
the abdominal muscles contract, and the stomach con- 
tent is thus forced out. The vomited material usually 
consists of particles of food admixed with mucus, although 
it may be composed entirely of a thin, shiny mucus. 
The expelled material may contain intestinal as well as 
gastric contents. 

Anemia 

Anemia of the mucous membrane of the stomach 
occurs in swine after surgical operations in which large 
quantities of blood have been lost. It may also be 
due to obstruction of the arteries supplying the gastric 
walls. 



THE DIGESTIVE SYSTEM 23 

A long-continued anemia of the stomach results in 
atrophy of its walls. An anemic stomach is pale, flabby, 
and bloodless. 

Gastric anemia results in improper digestion, which 
ultimately leads to emaciation and possibly to other 
disturbances of the animal body. 

Hemorrhage (Hematemesis) 

Etiology — Hemorrhage of the stomach, or hematemesis 
is the result of erosion of blood vessels due to diseased pro- 
cesses, traumatisms, and caustics. Hog cholera is the 
most frequent cause of gastric hemorrhages in hogs. 

Petechial hemorrhage into the walls of the stomach 
is associated with various infective diseases. 

Lesions. — Erosion or laceration of the blood vessels 
plus an accumulation of blood in the stomach or dis- 
charged from the stomach, are associated with gastric 
hemorrhage. The hydrochloric acid of the gastric juice, 
acting upon the blood, forms a clot, and also changes the 
color of the blood. As a rule the extravasation is con- 
verted into masses, which are of about the same size 
and color as roasted coffee beans. If the escaped blood 
from the stomach passes on through the intestine it will 
remain firmly clotted in coffee-bean masses. These 
masses characterize gastric hemorrhage and serve to 
distinguish gastric from intestinal hemorrhage. 

Symptoms. — Gastric hemorrhage is evidenced by a 
pale mucous membrane and the escape of non-frothy, 
black, and more or less coagulated masses of blood from 
the mouth. 

Peptic Ulcers 

Peptic ulcers are rarely observed in swine, but when 
they occur are usually near the pyloric end of the stomach. 

Etiology. — The cause of peptic ulcer is by some thought 
due to thrombotic formation: it may be due to the action 
of gastric juice upon anemic areas of the stomach. 



24 SWINE DISEASES 

Lesions. — Peptic ulcers are characteristic in their ap- 
pearance. They may involve the mucous membrane only 
or they may extend through the submucosa and involve 
the muscular coat of the stomach, and even perforate 
the serous membrane. In size they vary from that of the 
cross-section of a lead pencil to the area of a silver 
dollar. They appear as though made by means of a 
punch, and if they involve more than the mucous mem- 
brane they usually have a terraced margin; their walls 
being clean-cut and non-inflammatory. 

Symptons. — ^The evidences of peptic ulcer vary, but 
usually there is indigestion and occasionally hemorrhages. 
Sometimes it results in perforation of the stomach, 
followed by peritonitis and death. 

Hyperemia 

Passive hyperemia of the stomach is the result of 
obstructive circulation and usually is evidenced by more 
or less edema of the gastric walls; in extreme cases there 
may be thrombotic formation and focal or even extensive 
necrosis. 

Active hyperemia of the stomach is much more common 
than the passive form, and may be either physiologic or 
pathologic. 

Pathologic gastric arterial hyperemia is caused by 
irritation, either from chemicals, undue exposure, or 
infection, and represents the primary stage of inflam- 
mation. 

Gastritis 

Gastritis is relatively common in hogs. It results 
from traumatic injuries, chemical irritants (poisons), and 
infection. 

Catarrhal Gastritis 

Catarrhal gastritis is of fairly common occurrence 
and usually results from mild irritation. It is evidenced 
by a hyperemia of the mucosa, which appears red, slightly 
tumefied, and covered with varying quantities of mucus. 



THE DIGESTIVE SYSTEM 25 

Symptoms. — The symptoms of catarrhal gastritis 
vary according to the intensity of the disease, vomition 
after eating being one of the most common. There is 
usually increased thirst. In the beginning of the disease 
there is often constipation, followed by diarrhea with a 
discharge of a thin, fetid, fecal material. There is a 
slight rise of temperature and usually an unequal dis- 
tribution of surface temperature, one part being warm 
while another is cold. The tail drops, and the animals 
have a tendency to pile up or get under their bedding. 
The course of the disease is usually rapid and recovery 
almost certain. 

Treatment. — ^The treatment consists in determining 
the cause and then removing it. It is advisable to 
empty the stomach by use of an emetic, such as apomor- 
phin. The affected animals should then be placed on a 
diet consisting of a small quantity of easily digested food. 
Further treatment is rarely needed. 

Croupous Gastritis 

Croupous gastritis is usually the result of caustics 
ingested with food stuff, such as lye, which is occasionally 
fed in large quantities for the purpose of warding off 
diseases of various kinds. 

Lesions. — In croupous gastritis an intense tumefac- 
tion of the mucosa is present, the affected portion con- 
taining accumulation of exudate which is dirty white or 
brown in color, and when detached usually leaves a 
bleeding surface. 

Symptoms. — The manifestations of croupous gas- 
tritis are similar to those of catarrhal gastritis, but are 
more intense. The animals evince gastric pain by 
uneasiness, restlessness, and frequent vomition. There 
is a rise of temperature of from one to two degrees Fahren- 
heit. The affected swine have little desire to eat, but 
they show a tendency to drink frequently, after which 
they evidence more intense pain until they vomit. The 
tail hangs straight, and the animals have little tendency 
to move. 



26 SWINE DISEASES 

This disease usually runs a rapid course, as a rule 
terminating within five to eight days. 

The prognosis should be guarded. 

Treatment. — The treatment consists in giving 
demulcent drinks after having removed the cause. The 
content of the bowels should be kept soft by laxatives. 
The aflPected animals should be separated from the 
healthy and given good quarters. 

Phlegmonous Gastritis 

Phlegmonous gastritis occasionally occurs in hogs 
and is usually the result of infection with streptococcic 
micro organisms. 

Lesions. — The anatomical changes occurring in 
phlegmonous gastritis consist of an intense tumefaction 
of the mucosa due to accumulation of pus or other 
inflammatory products in the submucosa. Patches of 
the mucosa may become necrotic and desquamate. In 
other instances large sinuous tracts are formed beneath 
the mucosa and in these pus accumulates in large quan- 
tities. The muscular layers of the stomach frequently 
become infiltrated with pus; the inflammatory process 
may extend to and involve the serous coat. 

Symptoms. — The evidences of phlegmonous gas- 
tritis are not distinct and separable from those of croupous 
gastritis. There is usually intense pain, indicated by the 
constant change in position of the animals. Vomition is 
usually frequent, the vomited material being small in 
quantity and largely mucous or mucopurulent in char- 
acter, and it is not infrequently mixed with blood. There 
is inappetence, thirst, and a drawn-up appearance of 
the abdomen, with arching of the back. The temperature 
ranges from 104 to 107 degrees Fahrenheit. Constipa- 
tion is usually quite marked in the beginning, but may be 
succeeded by diarrhea. 

The course of this disease varies from three to seven 
days. The prognosis should be guarded, as the disease 
is usually fatal. 



THE DIGESTIVE SYSTEM 27 

Treatment. — The pain should be reheved by de- 
mulcent drinks, gastric lavage, and enemas, combined 
with anodynes. The medication of swine, especially of 
mature animals, is not an easy matter. 

Chronic Gastritis 

Chronic gastritis is of rather frequent occurrence in 
hogs and may be the result of irritation by the Arduenna 
strongylina. 

Lesions. — The anatomical changes in the stomach 
consist of a fibrous proliferation which may destroy the 
gland tissues or obstruct their ducts, resulting in the 
formation of small cysts. The mucosa is usually attenu- 
ated, due to atrophy of the mucous membrane. As a 
rule there is some ulceration and not infrequently the 
capacity of the stomach is diminished, due to the con- 
traction of the newly formed fibrous tissues. 

Symptoms. — The symptoms of chronic gastritis of 
swine are not distinct. There is variation of appetite. 
Vomition immediately after eating may or may not be 
present. Affected animals are unthrifty as a result of 
nutritive disturbances. 

This is essentiallj^ a chronic disease, the courses 
varying from a few weeks to months. Prognosis is 
favorable as to the life of the animal, but unfavorable 
as to the relief of the condition. 

Treatment. — Treatment consists in strictly limiting 
the diet to easily digested foods, and the maintenance of 
a laxative condition of the bowels. 

Dilatation 

Dilatation of the stomach may be acute or chronic. 

Acute Gastric Dilatation 

Acute dilatation is a condition resulting from a rapid 
distention of the stomach, a condition not very common 
in swine. 

Etiology. — Acute dilatation is usually due to over- 
loading the stomach. It is most frequently caused by 



28 SWINE DISEASES 

the ingestion of large quantities of indigestible substances, 
or of foods that are easily and extensively fermentable. 

Lesions. — The lesions observed in acute dilatation 
consist of enlargement, the walls being very much attenu- 
ated. Rupture of the stomach may occur in the greater 
curvature. 

Symptoms. — The evidences of acute dilatation are 
the same as those of overloading of the stomach. Rest- 
lessness, succeeded by vomiting, is the usual sign observed 
in the early stages of a limited dilatation. In some 
instances the walls of the stomach become so thin due 
to extreme distension, that vomition is not possible, 
and such cases are evidenced by gagging, salivation, and 
bloating, if the distension is due to foods that readily 
ferment. Extreme distension produces distress and 
expressions of pain. 

Diagnosis. — Diagnosis of gastric dilatation is depend- 
ent upon history and the symptoms indicated above. 
Prognosis should be guarded, as the possibility of rupture 
must always be considered. 

Treatment. — When the dilatation is not too great, 
the treatment should be largely confined to removal of 
the gastric content by emetics, and to lavage when the 
dilatation is extensive and likely to result in rupture. 

Chronic Gastric Dilatation 

Chronic gastric dilatation is not common in swine 
but has been observed. Accumulation of indigestible 
substances is the usual cause of the trouble. Occasional 
cases have been observed where there was a sufiicient 
accumulation of hair in the stomach to permanently 
dilate it beyond the normal capacity. 

Symptoms. — The usual evidences of chronic gastric 
dilatation consist of irregular appetite, associated with 
unthriftiness. The stomach is distended, and may con- 
tain various foreign bodies or indigestible substances. 
The gastric mucosa is usually affected with chronic 
catarrh. 



THE DIGESTIVE SYSTEM 29 

Treatment. — This condition is not very successfully 
treated because of the tendency to permanent dilatation 
of the stomach. Dieting, especially with easily digestible, 
concentrated foods, is especially advised. 

Tumors 

Tumors of the stomach of swine are not very preva- 
lent, or at least such cases are rarely reported. 

Fibromas have been observed in only a few instances. 
They usually involve the serous coat and rarely become 
of sufficient magnitude to cause damage other than 
slight mechanical interference. These tumors are in- 
variably incapsulated, and appear as a dense, fibrous 
mass. 

Lipomas occur in the serous coat of the stomach of 
swine though they are not common. A few such tumors 
have been observed, and in one instance the tumor had 
become so large that it seriously interfered with the 
function of the organ by displacing the stomach and 
producing such pressure that it practically occluded the 
duodenum and resulted in death. Lipomas appear as 
more or less nodular masses, and are invariably incapsu- 
lated. > 

Of the malignant tumors, carcinoma and adenoma 
have been observed, although they too are rather infre- 
quent and do not appear to be so injurious to the health 
of swine as the same kinds of tumors are to horses or 
even to cattle. Carcinomas may develop in the sub- 
mucosa and project into the lumen of the intestine 
as a cauliflower-hke mass, or they may develop 
in the mucosa, producing erosions not only of the 
mucous membrane, but of the other structures of the 
stomach wall, ultimately causing perforation and fatal 
peritonitis. These tumors are not incapsulated. 

The symptoms evolved as a result of tumors are quite 
variable and not sufficiently characteristic to permit a 
positive antemortem diagnosis. 

The treatment of gastric tumors is entirely surgical. 



30 SWINE DISEASES 



Parasites 



Arduenna strongylina is a very common parasite in 
the stomach of swine. In the central United States it is 
probable that at least ninety per cent of swine are infested. 
They are a small, thread-like, white worm, varying in 
length from three-fourths of an inch to one and one-half 
inches, usually more or less coiled, although they may be 
found practically straight. They may be found in masses 
in the submucosa, free upon the mucous membrane, 
extending into the gastric glands, or even perforating 
the mucous membrane. They injure their host by 
direct abstraction of nutriment, by obstruction of gastric 
glands, by destruction of tissue, and by irritation. The 
usual condition resulting from infestation with these 
parasites is chronic gastric catarrh. 

Symptoms. — Symptomatically the infestation with 
large numbers of the Arduenna strongylina is evidenced 
by variation of appetite, and usually by constipation, 
unthriftiness, and rough coat. It is doubtful if any 
symptoms would be sufficiently prominent upon which 
to base a diagnosis in cases in which the infestation is 
limited to a few worms. 

Treatment. — Treatment of gastric parasitism is 
not difficult providing the parasites are free upon the 
surface, but successful treatment is difficult in cases where 
the parasites have passed through the mucous membrane 
into the submucosa. The usual anthelmintic treatment 
is most easily applied in the food or slop. Ferrous 
sulphate, copper sulphate, or oil of turpentine may be 
mixed with slops. Santonin given with food is of value, 
but creosote in the slop is probably most efficient. 

The Simondsia paradoxa infests the stomach of 
swine, but is probably not found in the United States, 
although quite prevalent in some sections of Europe. 
The lesions, symptoms, and treatment are similar to 
those given for Arduenna strongylina. 

Ascaris suum is found occasionally in the stomach, 
but its natural habitat is the intestine, and it will be dis- 
cussed later in that relation. 



THE DIGESTIVE SYSTEM 31 

INTESTINES 

Malformations 

Total absence of the intestine is rare and occurs 
practically only in acardiac monsters. 

Atresia ani, that is, the failure of development of the 
anus, is relatively common. This condition results from 
the failure of invagination of the skin surface which 
normally extends to and fuses with the rectum. Pigs so 
affected, unless the defect is relieved by operation, die 
the first or second day after being farrowed. The 
defect is as a rule easily corrected by operation in which 
crucial incisions are made through the skin and the 
terminal end of the rectum, the skin and rectal triangular 
flaps being interdigitated and maintained by sutures. 

Cloacal formation in which there is a common opening 
for the intestine, uterus, and vagina or ureters sometimes 
occurs, but this is not a serious defect, except in breeding 
animals. 

Diverticula are not rare. They are usually the per- 
sistent remnants of the vitellin or omphalomesenteric 
duct. They do not as a rule interfere with the health of 
the animal. 

Transposition, particularly of the large colon, may 
occur, but is not of any significance except as a pathologic 
condition. 

Congenital hernia may occur. The outcome depends 
upon the extent and nature of the defect. 

Hemorrhage (Enterorrhagia) 

Enterorrhagia occurs rather commonly in swine. 

Etiology. — Mechanical injury of the structure of the 
intestine by ingested foreign bodies is a common cause of 
hemorrhage. In extreme cases of constipation the 
accumulated fecal matter may become so desiccated 
that it readily produces abrasions of the intestinal mucosa, 
resulting in hemorrhage. Parasites, particularly the 
Gigantorhynchus hirudinaceus, may also produce hemor- 
rhage. Intestinal hemorrhage is a common symptom of 



32 SWINE DISEASES 

hog cholera, anthrax, septicemia, cryptogamic poisoning, 
caustic poisoning, and severe inflammatory disturbances 
of the intestine. 

Lesions. — The particular lesion identifying intestinal 
hemorrhage is the extravasated blood which may or may 
not be thoroughly admixed with the intestinal content. 
If the hemorrhage has been extensive there will be a 
general anemia of the entire mucosa. Lesions of the 
intestinal mucosa will be observed in those cases in which 
the hemorrhage has been induced by trauma or chemical 
irritants. There may be no evidence of intestinal 
mucous membrane lesions in the infective diseases like 
hog cholera, as the hemorrhages in these cases are usually 
the result of blood-vessel lesions rather than mucosa 
lesions. 

Symptoms. — The first evidence of intestinal hemor- 
rhage is the passing of the blood from the anus. If the 
discharged blood is thoroughly admixed with the feces 
and of a brownish cast it indicates that the hemorrhage 
has been well forward in the small intestine. If the 
discharged blood occurs in masses, not mixed with the 
fecal matter, and has the normal blood color, it indicates 
that the hemorrhage has been in the anterior portion of 
the large intestine; and if the fecal matter is streaked 
with blood on the outer surface only, the hemorrhage 
occurred in the rectum. The visible mucous membranes 
will be pale, pulse rapid and almost imperceptible, and 
there will be weakness associated with uncertain gait. 

Diagnosis. — The diagnosis of enterorrhagia is usually 
not difficult, although it may not be an easy matter to 
determine the exact cause of the condition. In gastric 
hemorrhage the extravasated blood that passes through 
the bowel is granular and of a black color; the extra vasate 
from intestinal hemorrhage is massive, occurs upon the 
surface of the feces, and is normal in color. 

Treatment. — ^The treatment of intestinal hemorrhage 
is problematic, and the relief from this condition is 
dependent upon removing the cause, which is not always 
possible. The affected animals should be kept quiet. 



THE DIGESTIVE SYSTEM 33 

Ergot may be used to advantage. Astringents combined 
with laudanum may produce the desired results. 

Obstruction 

Intestinal obstruction is a condition resulting from 
the occlusion of the intestine by foreign bodies, inspissated 
fecal material, parasites, abscesses, tumors, cicatrices, 
rotation of the intestine upon itself or volvulus, and 
invagination or intussusception. Intussusception is not 
as common in the hog as in some other animals because of 
the arrangement of the mesentery, although it may, and 
sometimes does, occur. 

Lesions.- — The anatomical changes observed in 
intestinal obstruction vary according to the cause and 
duration of the condition. Thus foreign bodies, such as 
hair balls or nails, may be found; a tangled mass of 
Ascaris suum is sometimes the only lesion; abscess, tumor 
formation, or changed relation of the intestine may be 
the principal lesion. Aside from the obstructing agent 
there may be inflammatory or necrotic lesions of the 
mucous membrane or other portions of the intestine. 

Symptoms. — The first evidence is inappetence and a 
tucked abdomen, followed by infrequent defecation with 
the passage of small quantities of mucous-covered feces. 
Frequent attempts at defecation without the voiding of 
any fecal matter may occur. Vomition is a common 
symptom in the later stages. In some cases there is 
fermentation of the intestinal content with an excessive 
accumulation of gas, producing tympany. 

Treatment.— The relief of intestinal obstruction 
depends upon the cause. Obstruction from inspissated 
fecal matter may be overcome by the judicious use of 
saline laxatives or enemas. Parasitic obstruction may 
be overcome by the use of vermifuges given orally or in 
enemas. Relief from obstruction due to tumors or 
abscess formation may be temporarily obtained by 
purgatives, but permanent relief is obtained only by 
removing the cause. The treatment for obstruction 
from volvulus or intussusception is problematic and the 



34 . SWINE DISEASES 

outcome by no means certain. Surgical operation may 
be resorted to in overcoming these conditions, as well as 
in foreign-body obstruction. If the accumulations of 
gas cause alarming symptoms, the trocar may be used 
to produce immediate relief, and further fermentation 
may be checked by the administration of antiferments, 
either through the cannula or per os. As soon as the 
animals have a desire to eat they should be given sparingly 
of easily digested liquid foods. 

Dilatation 

Intestinal dilatation is not of common occurrence in 
swine. 

Etiology. — ^The usual cause is partial obstruction, 
resulting in excessive accumulations of food which produce 
atony and later a relaxation and dilatation of the intestinal 
walls. Should the dilatation be unequal, diverticular 
dilatation results. 

Lesions. — The usual lesions observed in intestinal 
dilatation consist of distended intestine with an accumu- 
lation of excessive quantities of food material in it and 
usually an associated condition that produces the primary 
obstruction. 

Symptoms. — Symptomatically, the dilatation is not 
positively differentiated antemortem from obstruction, 
the symptoms of both conditions being practically 
identical. 

Treatment. — In cases of dilatation, remove that 
which primarily causes an obstruction and then administer 
tonics to facilitate the return of intestinal tonicity. 

Emphysema 

Single air cysts or clusters of air cysts are not of 
infrequent occurrence, involving and protruding the 
serous coat of the intestine. This condition appears to 
produce no inconvenience and is of no particular economic 
importance. It has been thought to be the result of 
bacteria, probably of the colon group, which have pene- 
trated through the intestinal wall to the serous coat, 



THE DIGESTIVE SYSTEM 35 

where they produce fermentation and the gas evolved 
is accumulated beneath the serous membrane. These 
air cysts vary in size from a pinhead to a pea, and there 
may be only a limited number of them or myriads. 
Occasionally they are so prevalent that the intestine 
will float on water. 

Enteritis 

Enteritis is inflammation of the intestine and may 
be catarrhal, croupous, diphtheritic, mycotic; simple or 
infective, acute or chronic. 

Catarrhal enteritis may be either acute or chronic. 

Acute Catarrhal Enteritis 

Acute catarrhal enteritis is a common ailment of 
swine. 

Etiology. — The usual cause of this disease is improper 
food. The natural habits of swine are conducive to the 
introduction of various microbes into their food and 
drink, and swine are frequently fed on materials that 
are partially decomposed. Their food not infrequently 
contains chemical substances that are sufficiently irri- 
tating to establish a catarrhal gastritis and enteritis. 
The ingestion of foods of extreme temperatures may 
excite catarrhal enteritis; not infrequently parasites 
occur in sufficient numbers to produce local irritation of 
sufficient extent to result in catarrhal enteritis; finally, 
acute catarrhal enteritis may be associated with a variety 
of infective diseases. 

Lesions. ^ — The lesions may be localized or they may 
be general, involving practically the entire intestinal 
mucosa. In the beginning the affected mucous mem- 
brane is red, tumefied, and rather dry, but later it becomes 
coated with mucous which is produced in excessive 
quantities as the disease progresses. The submucosa 
may be swollen, due to the accumulation of inflammatory 
exudate. The tumefaction of the mucosa sometimes 
effectually closes the ducts of the intestinal glands, thus 
forming retention cysts, and the villi are turgescent and 



36 SWINE DISEASES 

have a velvety appearance. The lymphoid tissue usually 
becomes swollen and contains excessive quantities of 
leukocytes, which may be expressed as a milky substance. 
There may, in the advanced stages, be areas of necrosis 
of the epithelium of the mucous membrane. In the 
submucosa, hemorrhages of varying size may occur. 

Symptoms. — Acute catarrhal enteritis occurs most 
frequently in connection with acute catarrhal gastritis, 
and the symptoms of gastritis usually overshadow those 
of enteritis. Inappetence or variation of appetite, rise 
of temperature, listlessness, and arched back are common 
symptoms of acute gastrointestinal catarrh. The symp- 
toms of acute intestinal catarrh are frequent defecation 
of small quantities of mucous-coated feces. In the 
beginning, there is usually constipation, but this con- 
dition is succeeded by diarrhea. The affected animals 
groan and roll frequently. 

Treatment. — Remove the cause. Give easily di- 
gested foods when appetite returns. If constipation 
prevails, give some laxative, preferably oleaginous in 
character. Enemas of warm saline solutions sometimes 
give immediate relief. 

Chronic Catarrhal Enteritis 

Chronic intestinal catarrh is usually a sequel of acute 
intestinal catarrh. 

Etiology. — ^The usual causes of chronic intestinal 
catarrh are the same as those causing acute intestinal 
catarrh, but are continued over a longer period of time 
and probably, in the majority of instances, are not so 
intense. Error of diet is the most frequent cause. 
Chronic heart or liver diseases that produce venous 
engorgement of the intestine is a common cause. Para- 
sites, no doubt, are responsible for an occasional case of 
chronic intestinal catarrh. 

Lesions. — The affected mucous membrane is usually 
of a uniform or mottled bluish, steel, slate color. The 
mucosa is tumefied, dense, and of a leathery consistency 
due to the excessive development of fibrous tissue in the 



THE DIGESTIVE SYSTEM 37 

subniucosa. Small retention cysts representing occluded 
glands may be present. The covering epithelium of 
the mucous membrane is attenuated and sometimes 
erosions, or even ulcerations, are observed. 

Symptoms. — Irregular appetite, alternation of con- 
stipation and diarrhea, rough coat, emaciation, and 
malnutrition characterize chronic intestinal catarrh. 
The foregoing symptoms tend to persist, as the disease 
may continue for weeks. 

Treatment. — A proper diet combined with good 
surroundings are prerequisites for the successful treat- 
ment of cases of chronic intestinal catarrh. Regulation 
of the bowels, with maintenance of the proper con- 
sistency of the fecal matter, is highly important. Treat- 
ment must be persistent, as success will be attained 
only by a long-continued course of treatment, combined 
with the proper diet. 

Croupous and Diptheritic Enteritis 

Croupous enteritis probably occurs in swine, but is 
rather uncommon, while diphtheritic enteritis is fairly 
common. 

Etiology — The most common cause of diphtheritic 
enteritis is the Bacillus necrophorous, although some 
caustic chemicals may produce the condition. 

Lesions. — The lesions of diphtheritic enteritis usually 
occur in circumscribed areas or foci, although these may 
be disseminated over a large area of mucous membrane. 
In the beginning the affected portion is intensely red 
and tumefied, and later a coagulated exudate occurs 
upon the surface. This exudate is first of a dirty white 
or gray color, but may become brown or brownish-red 
and is not easily detached. After the condition has 
persisted for some time the affected areas have a scaly 
appearance due to the fact that the exudate becomes 
loose and later desquamates. 

Symptoms. — Colicky pains, restlessness, drooping 
ears and tail, increased thirst, usually diminished appetite, 
rise of temperature, and constipation alternating with 



38 SWINE DISEASES 

diarrhea are manifestations of diphtheritic enteritis. 
The affected animals rapidly become emaciated. 

Treatment. — Identify and remove the cause of the 
trouble. Oleaginous laxatives are indicated, and should 
be followed with demulcents. When the swine show an 
inclination to eat, give sparingly of easily digestible 
foods. 

Toxic Gastritis, Gastro-Enteritis, Enteritis 

A variety of conditions have been grouped under 
this heading, but this number fortunately is becoming 
less as more exact investigations are being concluded. 
It is difficult to clearly distinguish between toxic gastric, 
toxic gastro-intestinal, and toxic intestinal conditions, 
and as a matter of common observation it has been 
found that substances that ordinarily produce toxic 
gastritis have not spent their entire force in the stomach, 
and thus continue their action in the intestines. On the 
other hand, few if any substances are toxic in the intestine 
that are not also toxic in the stomach. 

Poisoning 
Sodium Chlorid {Common Salt) 

Poisoning with common salt is rather common. 
Swine may obtain this salt in cattle yards, or it may be 
given them in garbage. Meat brine is a frequent source 
of salt poisoning and is very destructive, as, unfortunately, 
swine appear to relish it. Brine poisoning is not only 
due to the contained salt, but also to other ingredients. 
It has been found that from two to eight ounces of salt 
produce poisoning in swine, and in some instances much 
smaller quantities are fatal. 

Lesions. ^ — Sodium chlorid is an intense gastro- 
intestinal irritant, particularly when in a concentrated 
solution. In the beginning the mucous membrane of the 
stomach will be intensely congested. This is followed by 
hemorrhages upon the mucous membrane, and inflamma- 
tory disturbances. If absorption is retarded the stomach 
and bowel content will contain large quantities of blood. 



THE DIGESTIVE SYSTEM 39 

The mucous membrane of the bladder will be engorged, 
and similar lesions may be observed in the meninges. 

Symptoms. — Intense thirst, inappetence, restless- 
ness, and vomition are usually the first symptoms evi- 
denced. Later there will be watery diarrhea, frequent 
urination, depressed heart action, muscular weakness, 
and paralysis. The animals may die within five or six 
hours after ingesting the salt, or they may not die until 
the second or third day; if the quantity consumed has 
been small, they may survive. 

Treatment. — Emetics should be employed if the 
animals are observed immediately after consuming the 
salt. In cases of several hours' standing, mucilaginous 
drinks and rectal injections should be given. Oleaginous 
purgatives may be of value as eliminants. Heart stimu- 
lants should be provided to avoid cardiac depression.^ 

Caustic Potash, Caustic Soda {Lye; Washing 

Powders) 

It is a common practice to feed swine wash water, 
particularly water that has been used for washing dishes 
and in which liberal quantities of washing .powder or 
lye have been used. Some swine breeders and feeders 
add varying quantities of lye to the feed to "ward off 
disease." 

Lesions. — Caustic alkalies may produce congestion, 
inflammation, or necrosis, depending upon the concen- 
tration of the mixture. The lesions will be diffuse if 
the alkali has been in solution; they will tend to localiza- 
tion if the alkali has been in the powdered form. In 
the latter case the lesions occur where the alkali granules 
have been deposited upon the mucous membrane. The 
lesions are usually more intense in the stomach than in 
the intestine. 

Symptoms. — Wretching, vomition, restlessness, and 
muscular weakness are the usual symptoms evidenced in 
the beginning, followed later by diarrhea, incoordination, 

^Poisoning by herring brine produces, in addition to toxic gastro- 
enteritis, cerebral disturbances very similar to ptomaine poisoning. 



40 SWINE DISEASES 

and paralysis. Death may occur within a few hours or 
in two or three days. Some of the affected animals may 
recover. 

Treatment. — In the early stages emetics should be 
given until vomition is produced. Later acidulated 
water and oleaginous purgatives will be of value. 

Phosphorous 

In some sections of the country phosphorous com- 
pounds are used in destroying gophers, squirrels, and 
other similar animals, and not infrequently swine obtain 
a sufficient quantity of the poison to produce grave 
disturbances and even death. 

Lesions. — The buccal, pharyngeal, gastric, and in- 
testinal mucosa show inflammation. The liver and 
kidneys are enlarged, due to fatty degeneration of their 
parenchyma, and the heart also is usually affected by 
fatty changes. The content of stomach and bowel are 
phosphorescent when examined in the dark, and a dis- 
tinct phosphorous odor emanates from the stomach and 
bowel when these organs are opened. 

Symptoms. — Intense thirst, difficult deglutition, 
vomition, and colicky pains, associated with weakness 
and incoordination, are produced by phosphorous poison- 
ing. 

Treatment. — Emetics and the administration of 
turpentine in mucilaginous substances, when applied 
energeticall3^ will sometimes save the patient. 

Xanthium Canadense (Cocklebur) 

Cocklebur poisoning prevails more or less extensively 
in the Missouri Valley during the early spring months. 
Just as the two cotyledons push through the ground is 
the only time in the development of the cocklebur that 
it is poisonous, or possibly swine eat the plant only during 
this stage of development. The writer assisted in an 
investigation of the effect of young cockleburs when 
eaten by swine at the Kansas Agricultural Experiment 
Station in 1899. Quantities of the young plants were 



THE DIGESTIVE SYSTEM 41 

gathered and fed to pigs weighing from forty to 
sixty pounds. The symptoms, although not univer- 
sally the same in all cases, clearly indicated a 
gastro-enteritis, which was verified by autopsy. 

Lesions. — There is evidence of a marked gastro- 
enteritis in animals dead of cocklebur poisoning, usually 
involving the entire mucosa of the stomach and the 
small intestine and not infrequently extending to the 
mucous membrane of the large intestine. The involved 
mucous membrane may slough, leaving large areas of 
denuded surface. 

Symptoms. — Increased thirst, colic pains, diarrhea, 
weakness, paralysis, and death succeed one another 
rather rapidly in fatal cases. In some instances the life 
of the affected animal is prolonged for several days, 
during which time there is rapid emaciation. 

Treatment. — ^Treatment is not satisfactory. In the 
early stages emetics may be of value, followed by purga- 
tives and mucilaginous drinks. 

Atropa Belladonna {Deadly Nightshade) 

Deadly nightshade poisoning is not of frequent 
occurrence, although it has been reported in sections of 
the country where the plant grows. 

Lesions. — The lesions are not characteristic. Animals 
that die within a few hours will show no lesions at all, 
except retention of the urine or a greatly distended 
bladder; the blood may be somewhat darker than normal. 
Those that are affected for one or more days will show a 
gastro-intestinal inflammation. 

Symptoms. — The first symptoms noticed are nausea, 
followed by vomition, dryness of the mouth, more or 
less excitement and convulsions, increased pulse and 
respiration, dilated pupils, and partial bhndness. The 
duration of this period is short and is followed by paralysis. 
The animals become weak, and stagger, the temperature 
falls, respiration is slow and weak, gradually becoming 
shallower, the pulse is rapid and weak, and there is a 
relaxation of the sphincter muscles. The affected 



42 SWINE DISEASES 

animals soon pass into a state of coma in which death 
takes place, probably due to asphyxiation and cardiac 
failure. 

Treatment. — Treatment consists in administering 
the antidotes of atropin; emetics and purgatives; in 
stimulating the heart, and in resorting to artificial res- 
piration. If there are periods of excitement, or con- 
vulsions, the animal should be given sedatives. A 
valuable aid in correctly diagnosing deadly nightshade 
poisoning consists in taking a few drops of urine of the 
dead animal and dropping it into the conjunctival sac 
of a normal or healthy animal. If the poisoning is due 
to atropin, or deadly nightshade, a dilatation of the 
pupil will occur. 

The carcasses of animals that have died of deadly 
nightshade poisoning putrify very slowly. 

Garbage 

This is the time of conservation, and although the 
feeding of garbage to swine is not in keeping with present 
sanitary requirements, it is upheld by some as a means 
of utilizing products that would otherwise be wasted. 

In the past rather extensive losses from garbage 
feeding have been reported, but since the advent of 
anti-hog cholera serum it has been found that many of 
the cases formerly reported as garbage poisoning were 
hog cholera, and it is certain that garbage frequently is 
contaminated with the virus of hog cholera. 

Garbage poisoning does not signify any one definite 
kind of poisoning. From the various reports of investi- 
gators it is found that powdered soap, salt, brine, phos- 
phorous, and arsenic are the most common active causes, 
although occasionally, no doubt, ptomaines are a factor. 
Because of the nature of the poisonous substance, cooking 
the garbage is of little value. 

Lesions. — The lesions of garbage poisoning vary and 
are dependent upon the specific poisonous principle. In 
practically all cases there is evidence of gastro-enteritis, 
which may or may not be associated with hepatitis, 



THE DIGESTIVE SYSTEM 43 

nephritis, or cystitis. In some instances, for example, 
those cases dying of strychnin poisoning, no lesions will be 
found. 

Symptoms. — The symptoms, like the lesions, are 
variable and depend upon the nature of the poison. 
There is usually vomition and diarrhea, associated with 
listlessness and drooped ears and tail, and as a rule there 
is marked evidence of colic. The affected animals may 
die suddenly or they may linger for several days; some of 
them may recover. 

Treatment. — The further feeding of the polluted 
garbage should be prohibited. Emetics, enemas, and 
purgatives to effectuallj^ remove the offending material 
are indicated in the beginning. If the specific poison is 
known, the antidote should be given. In the later 
stages, treatment of the various symptoms as they arise 
is good practice. 

Cryptogams (Molds, Yeast, Bacteria) 

No doubt some forms of garbage poisoning are due to 
molds, yeast, or bacteria that are capable of producing 
injurious substances in the alimentary canal or have by 
their growth and activity produced injurious substances 
in or upon the foods prior to the time of their ingestion. 
Gastro-enteritis resulting from the action or products of 
the above-mentioned vegetable microorganisms is desig- 
nated cryptogamic poisoning or mj^cotic gastro-enteritis. 

This condition is not so common in swine as in some 
other domestic animals, notably the horse. Glover, of 
the Colorado Agricultural Experiment Station, has 
reported outbreaks of such a disease which were probably 
due to bacterially decomposed potatoes. Some un- 
authentic cases have been reported of this condition 
arising from the consumption of moldy alfalfa. Cases 
have been observed, but not frequently, of swine that had 
been fed ui)on moldy corn dying of mycotic gastro- 
enteritis and cerebritis. 

Lesions. — There is considerable variation in the 
postmortem findings in swine that have died of mycotic 



44 SWINE DISEASES 

gastro-enteritis. This is not extraordinary, for there is 
a variety of molds that cause this condition. One 
usually finds extensive inflammation of the gastro- 
intestinal mucosa, and in cases that have lingered for 
some time, ulcerations are very common. There is 
frequently meningeal engorgement, and in rare cases 
there may be cerebral softening. 

Symptoms. — There is inappetence, increased thirst, 
rise of temperature, constipation succeeded by diarrhea, 
weakness, and rapid emaciation. 

Treatment. — Little can be done to relieve this con- 
dition. Symptomatic treatment is of some value, and 
should be applied. 

Cotton-Seed Meal 

Fatal results frequently, but not always, attend the 
feeding for long periods of cotton-seed meal to swine. 
From experiments thus far conducted it is apparent that 
cotton-seed as a feed is more applicable to ruminants 
than to swine. The feeding for short periods has in 
many instances been beneficial. 

Lesions. — On autopsy, excessive quantities of a 
serous fluid are found in the pleural and peritoneal 
cavities. The lung is congested, inflamed, and frequently 
edematous. Congestion in all internal organs may be 
observed. 

Symptoms.— The feces are firm, although diarrhea 
may be present. Unthriftiness, irregular appetite or 
inappetence, weakness, unsteady gait, blindness, and 
dyspnea are common symptoms. The animals finally 
assume the decubital position, and may struggle or may 
become comatose. Death occurs in from a few hours 
to several daj^s, sometimes occurring almost instan- 
taneously with premonitory symptoms. 

Treatment. — Green feed and exercise have a tendency 
to counteract the injiu-ious effects of cotton-seed meal. 
Free access to wood ashes is a valuable but not an absolute 
preventive of cotton-seed poisoning. Iron compounds 
have also been used and proved beneficial, while the wood 



THE DIGESTIVE SYSTEM 45 

ashes and iron salts are preventive but not curative 
agents. The treatment of affected animals has not been 
successful. 

V 

Scours in Sucklings 

In some sections of the country scours in suckling 
pigs has become a menace to the swine-raising industry. 

Etiology. — There is apparently no single cause that is 
responsible for the various cases of scours. Unfavorable 
surroundings, such as damp, dark, and dingy hog houses, 
predispose to this condition. In some instances, mammitis 
of the sow is a causative factor. Improper foods, such as 
moldy or fermented slops, probably result in elimination 
of injurious substances in the mother's milk that will 
create in the pigs digestive disturbances resulting in 
diarrhea. Scours may also result from infection with 
modified colon bacilli. Bacillus necrophorous and, it has 
been reported, certain coccidia are responsible for a type 
of diarrhea that is frequently fatal to suckling pigs. It 
is probable also that intestinal parasites may be respon- 
sible for catarrhal enteritis and an associated diarrhea. 
Artificial feeding is likely to produce digestive derange- 
ment and diarrhea, and exposure to extreme temperature 
variation must be considered as a causative factor of 
pig diarrhea. This condition may occur in pigs varying 
in age from two days to several weeks. 

Lesions. — There are no constant lesions associated 
with scours in pigs. The intestinal content is usually 
quite liquid and may be putrid. Parasites may be 
observed. Some irritation of the intestinal mucosa may 
obtain, and there may be ulcerations. 

Symptoms. — In pig^ diarrhea the evacuations are 
pasty, the discharges being of a grayish or slate color. 
Later the discharge becomes more w^atery and fetid, 
and the pig's tail and hind parts become soiled. Some 
pigs eat heartily, while in others the appetite gradually 
diminishes. The affected pigs evidence some abdominal 
pain. They emaciate rapidly, become weak, and soon 



46 SWINE DISEASES 

appear dejected and dull, having an arched back and an 
indisposition to move. 

Treatment. — If possible, remove the cause. Give 
proper diet to the sow and have clean, wholesome sur- 
roundings for the pigs. Medicinal treatment of the 
affected pigs, particularly those depending entirely upon 
their mother's milk, is difficult. It is a good practice 
to hasten the removal of the irritating substances from 
the bowel, by the use of castor oil or similar purga- 
tive. If the diarrhea persists after the correction of 
diet and the action of castor oil, small quantities of 
bismuth subnitrate may be used to advantage. Intes- 
tinal antiseptics, such as salol and the sulphocarbolates 
of sodium, calcium, and zinc, are exceedingly beneficial 
where they can be administered frequently. 

Parasites 

The intestine of swine is a common abode for para- 
sites. Parasitic infestation is most prevalent in young 
animals, but because of the mode of eating and the 
habits of swine it is rather the exception to find even 
an old hog entirely free from intestinal parasites. Their 
injury to the host depends upon the kind and the number 
of parasites. Intestinal parasites injure swine as follows: 

1. Abstraction of nutrition. 

2. Obstruction. 

(a) Of the lumen of the intestine. 

(b) Of the lumen of the hepatic duct. 

3. Irritation of mucous membrane due to movement. 

4. Irritation of mucous membrane due to lip attach- 
ment resulting in inflammation, necrosis, and ulceration. 

5. Liberation of chemical substances that produce 
nervous irritation or hematolysis. 

The following parasites infest the intestine of swine: 

1. Ascaris suum. 

2. Esophagostoma dentatum. 

3. Trichocephalus crenatus. 

4. Trichinella spiralis. 

5. Gigantorhynchus hirudinaceus. 



THE DIGESTIVE SYSTEM 47 

Ascaris Suum 

Ascarids are found in practically all hogs. They are 
not blood suckers, but obtain their nutrition by direct 
absorption. The pregnant female discharges her ova 
in the intestine and they pass out with the feces, where 
they hatch and, so far as known, pass through a portion 
of their life cycle in decaying matter on the earth's 
surface and later gain entrance to the animal body with 
the food or drink. 

Lesions. — These parasites are round, and pointed at 
either end; they are white or pinkish- white in color and 
vary from six inches to twelve inches in length. Usually 
they are found in the small intestine, though they may 
occur in the large intestine and even in the stomach. 
They attach themselves to the mucous membrane by 
means of papillae or membranous teeth, and produce 
irritation to the mucous membrane as well as providing 
an avenue of entrance for a variety of bacteria which may 
produce inflammatory lesions and even necrosis and 
ulceration. The entire mucous membrane adjacent to 
the parasites is affected by a catarrhal inflammation. 
Similar disturbances are observed in the mucous mem- 
brane of the hepatic duct when it is infested. The 
worms may form a mass that completely obstructs the 
intestine, resulting in an engorgement of the intestine 
anteriorly to the obstruction. Occasionally the intestine 
may be perforated and the offending ascarids found 
protruding into the peritoneal cavity, or they may 
pass through the intestinal wall and some of the intes- 
tinal content, and, escaping into the peritoneal cavity, 
will produce a general peritonitis. 

Symptoms. — Infestation with a limited number of 
ascarids probably does not produce any noticeable 
symptoms. The symptoms evidenced will vary and 
depend upon the manner in which the parasites are 
damaging their host. If the hepatic duct is obstructed, 
there will be digestive disturbances, associated with 
icterus. If the bowel is obstructed, there will be evidence 
of obstruction colic. Perforation of the bowel will 



48 



SWINE DISEASES 



result in peritonitis. The presence of several of these 
parasites may be suspected when there is catarrhal 
enteritis, especially when the swine are being properly 
cared for and given a proper diet of wholesome food. 
Usually an occasional worm will be passed in the feces. 
Unless infestation is sufficiently extensive to produce 




Fig. 3.— ASCARIS SUUM. 

visible symptoms, a positive diagnosis may not be made 
until the parasites are eliminated or the ova are identified 
in the feces by microscopic examination. If this con- 
dition persists for some time the affected animals become 
unthrifty and emaciated. 

Treatment. — Prevention is far more satisfactory 
than treatment of infested hogs. The extent of infesta- 



THE DIGESTIVE SYSTEM 49 

tion can be materially diminished by keeping the quarters 
clean. The droppings should be gathered and limed, 
and the floors in the piggery should be kept clean, and 
limed or sprayed with some agent that is destructive to 
the egg and embryo of the ascarids. Common salt 
destroys the embryo and larvae of practically all animal 
parasites, but it must be used with caution in hog premises, 
for it is also quite destructive to hogs. 

Treatment of individual hogs by giving direct medi- 
caments is difficult. The most effectual method of 
medicating swine, particularly when large numbers are 
to be treated, is accomplished by medicating the slops 
or feed. Santonin and areca nut have been used, but 
other less expensive and as effectual drugs may be selected, 
such as ferrous sulphate, copper sulphate, and creosote. 
When drugs are mixed with slops or feed, care must be 
used to have a thorough mixture, and each hog should 
obtain its proper portion. The medication in slop or 
food should be given once a day and continued for several 
days. The excrements laden with the worms and their 
ova should be properly disposed of in order that future 
infestation may be diminished.^ 

Esophagostoma Dentatum 

Esophagostomiasis is a disease caused by the invasion 
of the Esophagostoma dentatum into the submucosa 
of the large intestine of swine, a condition not very 
common in America. This parasite is parasitic in its 
larval stage. Its life cycle has not been entirely worked 
out, but the ova are discharged from the animal body 
in the feces and hatch, if climatic conditions are favorable, 
into embryos. Later changes are unknown, but the 
larvae are ingested with food or drink and bore into the 
submucosa of the large intestine, where they remain 
from six to seven months and produce small nodules 

^The external covering of the ascarids contains a volatile chemical 
substance that is extremely irritating to the ocular mucous membrane, 
and care should be exercised that the hands be carefully cleansed after 
handling these worms and thus prevent the development of conjunc- 
tivitis. 



50 SWINE DISEASES . 

in which they undergo various metamorphoses, finally 
becoming sexually mature. They then leave the sub- 
mucosa nodules and migrate into the lumen of the 
intestine, where copulation occurs and the female later 
ovulates in the same location. 

Lesions. — The principal lesion is the submucous 
nodules that occur in the large intestine. There may 
be only a few nodules, or there may be many. These 
nodules are inflammatory, caused by the presence of 
the larvae. They are definitely circumscribed with a 
fibrous capsule; the content of which is inflammatory 
exudate that later becomes purulent, then caseous, and 
may ultimately calcify. The nodules first cause a slight 
hard, spherical elevation of the mucous membrane about 
the size of millet seed, but they may later become as 
large as a pea. In the later stages they assume a greenish- 
gray cast due to the accumulation in them of pus. The 
nodules frequently produce erosions and ulceration of 
the intestinal mucosa, and they may persist and appear 
as caseated incapsulated masses. The adult parasites 
may be found free in the large intestine. They are 
about three-fourths of an inch in length. 

Symptoms. ^ — The extent of invasion sufficient to 
produce visible symptoms has not been determined, 
but it is not uncommon to find a few nodules in the 
intestine of swine that were slaughtered in packing 
houses and were known to have been previously healthy. 
The usual symptoms consist of a profuse and persistent 
diarrhea, emaciation, weakness, and death in the intensely 
infested animals. The disease is essentially chronic. 
The course is from two to three months. 

Treatment. — Because of the location of the offending 
larvse, medication is of no avail. A small percentage 
of the animals may be saved by dieting and treating 
the symptoms as they arise. Prevention of further 
spread of the disease should be the chief consideration. 

Trichocephalus Crenatus 

This parasite is not of common occurrence in America. 
The worms are in shape similar to the old-fashioned 



THE DIGESTIVE SYSTEM 51 

blacksnake whip, the head end very thin and hair-Uke, 
the posterior extremity being thicker and thread-like. 
They are usnally coiled, and are from one to one and one- 
quarter inches in length. Their life cycle is similar to 
that of the Esophagostoma. Infestation is accomplished 
through the food or drink. 

Lesions. — The Trichocephali are blood suckers, but 
they appear to do very little damage unless they occur 
in large numbers. When they produce anemia there is 
also more or less intestinal catarrh. The parasites are 
found firml}'^ attached to the mucous membrane of the 
large intestine. 

Symptoms. — The principal symptoms are diarrhea, 
emaciation, and weakness. 

Treatment. — Practically the same as described for 
the Ascaris suum. 

Trichinella Spiralis 

Trichinella spiralis passes only the adult stage of its 
life cycle in the intestine. The larvae are important 
muscle parasites. Further discussion will be found 
under "Muscular Parasites," on page 142. 

Gigantorhynchus Hirudinaceus 

This, the thorn-headed intestinal worm of swine, is 
quite prevalent in practically all sections of this country. 
It is a thick, cylindrical, white worm with an attenuated 
tail portion, transverse markings, and a head provided 
with a globular proboscis having several rows of hooks. 
The ova pass to the ground with the feces and are ingested 
by the larva of the May beetle, in which it passes a 
portion of its life cycle, the embryo and larval stages. 
Hogs consume the May-beetle larva and the inclosed 
gigantorhynchus larva is liberated and passes into and 
attaches to the intestine of the hog. It is thought that 
the ova may develop elsewhere as well as in the May- 
beetle larva. 

Lesions. — Upon opening the abdomen of a swine 
infested with the Gigantorhynchus, shiny nodules of a 



52 



SWINE DISEASES 



grayish color are readily visible on the serous coat of the 
intestine. The thorn of the worm is found to have 
penetrated the mucosa, and thus permits of infection 
which results in the production of an inflammatory zone. 
The parasites may become detached, the lesions pro- 
duced having healed by the formation of cicatricial 




Fig. 3.~GIGANTORHYNCHUS HIRUDINACEUS. 



tissue, which is usually easily recognized. Not infre- 
quently the head of the parasite bores through the 
entire intestinal wall and occasions general peritonitis. 
Symptoms. — The usual symptoms consist of di- 
gestive disturbance the magnitude of which will depend 
upon the extent of infestation. The infested animal 
usually gives evidence of pain, as the parasite lacerates 



THE DIGESTIVE SYSTEM 53 

the tissues during its attachment. There may also be 
muscular twitching. 

Treatment. — These parasites are difficult to dis- 
lodge. Long-continued medication with creosote alter- 
nated with copper sulphate has proved effectual in many 
cases. 

Tumors 

Intestinal tumors are not prevalent and are of little 
economic importance. 

Connective tissue tumors may develop and mechani- 
cally interfere with intestinal movement or they may 
obstruct the lumen of the bowel. Fibromas and myxomas 
have been observed, usually having their origin in the 
subserosa or within the serous coat of the intestine. 
These tumors are definitely encapsulated. It is usually 
not possible to make a diagnosis except by autopsy. 

Of the malignant tumors, carcinoma, epithelioma, 
adenoma, and different varieties of sarcoma have been 
identified. The embrj^onic epithelial tumors may be 
primary or secondary. Primary epithelial tumors usually 
have their origin in or from the mucous membrane. 
Secondary epithelial tumors may involve any portion 
of the intestinal wall and are more frequently encapsu- 
lated than the primary tumors. The primary epithelial 
tumors, especially epitheliomas, are very prone to pro- 
duce necrosis of the surface mucous membrane and thus 
cause ulceration. 

General sarcomatosis of the entire abdominal viscera 
is occasionally observed. Sarcomas in swine are appar- 
ently not so malignant as in other domesticated animals, 
and are more frequently encapsulated. The appearance 
of the various malignant tumors in swine is the same or 
very similar to that of the same type of tumor in other 
animals. 

Intestinal malignant tumors, generally speaking, are 
evidenced by unthriftiness, indigestion, emaciation, ma- 
rasmus, and finally by death. 



54 SWINE DISEASES 

LIVER 

The liver is a very important organ physiologically, 
and it is of such magnitude that derangement of its 
function and disease usually result in marked metaboKc 
disturbance of the affected animal. The diseases of 
the liver of swine have not received the attention pro- 
portional with other diseases; in fact, little is known of 
the pathologic conditions in the liver of swine excepting 
those observed and recorded by men employed in the 
inspection of meat. 

Malformations 

Malformations of the liver are not of much importance. 
There may be too few or too many lobes. The lobes 
may be entirely separated. Rarely, the gall bladder is 
wanting. 

Foreign Bodies 

Several hog livers have been observed that contained 
quantities of sand or cinders, varying in volume from 
an ounce to a quart.' These cases have been observed 
in swine killed at abattoirs, and without exception the 
affected animals were in prime condition. 

The avenue of entrance of the sand and cinders is 
no doubt through the hepatic duct. Just ' how the 
foreign substances gain entrance and "back-tell" in the 
ducts to the gall bladder and from there into the col- 
lecting cystic ducts in the liver has not been determined. 
The hepatic duct orifice in the summit of the duodenal 
papilla probably becomes enlarged through injury, or 
atrophy of the surrounding mucosa, and this, in con- 
junction with a full stomach and intestine, would facili- 
tate the passage of the foreign substance through the 
orifice and into the hepatic duct. The irritation of the 
foreign substance may cause relaxation of the sphincter 
muscles and also establish reverse peristalsis. It may 
be possible that the cause may be due to irregular action 
of the intestinal musculature. In all of the cases observed 
the hepatic duct was found gorged with the foreign 



THE DIGESTIVE SYSTEM 55 

material, the duct in some instances being more than 
one inch in diameter; the cystic duct and gall bladder 
were found to contain varying quantities of the same 
material. In one case the gall bladder was so engorged 
with sand that it had dilated until it was fully as large 
as a quart measure. The foreign substance, either 
cinders or sand, may also be found in the ducts that 
convey the bile to the gall bladder. In some instances 
the biliary capillaries contained considerable quantities 
of sand. The accumulations obstructing the outflow of 
bile result in icterus of varying intensity. There is 
also a catarrhal inflammation of the adjacent intestinal 
mucosa and the mucous membrane of the bile tubules, 
gall-bladder, and hepatic duct. 

Rupture 

Rupture or laceration of the liver does occur, although 
it is not so common in swine as in most other animals 
because the abdominal wall of swine is comparatively 
thick, due to the deposition of subcutaneous fat. 

Etiology. — The usual cause of hepatic rupture is 
mechanical interference in the form of a sudden blow, 
such as the kick of a mule or the penetration of the 
liver with some sharp object which may lacerate the 
hepatic tissue. 

Lesions. — If the hepatic lesion has caused sudden 
death the peritoneal cavity will contain a large quantity 
of blood which may or may not be coagulated, depending 
upon the length of time after death that the autopsy 
is conducted. If the injury is an old lesion, cicatricial 
tissue will have sealed the wound and perhaps, by con- 
traction, distorted the liver. 

Symptoms. — The symptoms evidenced will be shock, 
weakness, and blanched visible mucous membranes due 
to loss of blood from the blood vascular system. Should 
the animal survive the immediate affect of the injury 
and the loss of blood, there may be symptoms only of 
impaired hepatic function, or there may be no visible 
symptoms. 



56 SWINE DISEASES 

Treatment. — Because of the nature of hepatic 
rupture, treatment is of no avail. In cases that will 
probably have a fatal termination the animal may be 
bled to death and the carcass thus saved for meat. 

Icterus 

Icterus or jaundice is a condition resulting from the 
deposition of bile or bile pigments in the various tissues. 
This condition is relatively common and is significant as 
a diagnostic factor. 

Etiology. — Icterus may be the result of obstructed 
outflow of bile. It may result from excessive destruction 
of red blood cells, of failure of elimination of bile from 
the blood. Obstructed outflow of bile may be due to 
calculi, parasites, or foreign bodies in the bile ducts, 
closure of the duct by cicatrices, muscular spasms, 
tumors, abscess, aneurysms, fecal matter, parasitic 
cj^sts, or inflammatory disturbances of the mucous 
membrane of the duodenum or the various bile ducts. 
Excessive production of bile in the blood occurs as a 
result of hemolysis due to chemic substances in such 
diseases as hog cholera, swine plague, septicemia, pj^emia, 
generalized anthrax, phosphorous poisoning, and also 
as a result of the injection of the venom of some 
poisonous snakes. Failure of elimination of bile occurs 
not only when the outlets are obstructed but also when 
considerable numbers of liver cells have been destroj^ed 
or their functional capacity diminished. 

Lesions. — Bile staining is most evident in the con- 
junctiva and ocular sclera of the living animal, where 
it produces a lemoa-yellow or greenish-yellow discolora- 
tion. If the reabsorption of bile is very extensive it 
may appear in the urine. In carcasses biliary pig- 
mentation is most evident in the adipose tissue, especially 
the subcutaneous fat, although it is usually well marked 
in the subserous fat and may be detected in the lymph 
nodes, spleen, kidney, and muscular tissues. On micro- 
scopic examination the bile pigments may be found in 



THE DIGESTIVE SYSTEM 57 

the cells or between the cells as greenish-yellow amorphous 
granules. 

Symptoms. — The effects of icterus are variable. 
The tissues are discolored; there may be pruritis, cardiac 
depression, vomition, coma, and death. The symptoms 
above outlined are probably not due to the presence of 
the bile pigments in the tissue, but to other substances 
that have not been eliminated. 

Treatment. — Removal of the cause is usually all 
that is required for complete recovery from icterus. If 
the cause cannot be identified, then the symptoms should 
be treated as they arise. 

Cloudy Swelling 

Cloudy swelling, or parenchymatous degeneration, is 
a condition in which a portion of the cell protoplasm is 
coagulated. This condition is very common. It is 
frequently the forerunner of fatty changes. 

Etiology. — Coagulation of portions of the cell proto- 
plasm may be caused by high temperature, as is evidenced 
in fever or overheat, or it may be caused by bacterial 
products and other chemical poisons. 

Lesions. — The affected liver is enlarged, paler in 
color, and more friable than normal. 

Symptoms. — The symptoms are usually associated 
with those of other disturbances and are therefore not 
specific. There is evidence of disturbed hepatic function, 
and often a slight icterus and tendency to constipation. 

Treatment. — To ascertain and then remove the 
cause is of prime importance. This condition is corrected 
only through the efforts of the body, therefore, provide 
the proper diet and maintain sanitary conditions. 

Fatty Changes 

Fatty changes in the liver are of common occurrence 
in swine. The usual change is first an accumulation of 
fat droplets between the cells and later a fatty degenera- 
tion of the cells. 



58 SWINE DISEASES 

Etiology. — Fatty changes in the hver may be due to 
excessive nutrition, diminished exercise, hereditary in- 
fluences, long-continued fever, bacterial products, and 
such chemical poisons as phosphorous. Fatty degen- 
eration of hepatic tissue is sometimes observed in con- 
ditions associated with malnutrition. 

Lesions. — The liver is enlarged, gray or grayish-red 
in color and lighter than normal in weight; when incised, 
droplets of fat or oil may be observed on the knife. 
Fatty changes are usually uniformly distributed in the 
entire liver; however, in exceptional cases, one lobe 
only may be involved. 

Symptoms. — The evidence of fatty changes in the 
liver are not characteristic. The condition may be 
suspected in obese animals or those known to be affected 
with chronic arsenic, antimony, or phosphorous poisoning. 

Treatment. — There is no treatment that is of any 
special value more than to correct the diet. 

Amyloid Changes 

Amyloid changes in the liver are rather uncommon 
in swine. The cause is unknown. The affected liver is 
larger, paler, and firmer than normal. The amyloid 
areas are homogenous and translucent in appearance, 
the amylaceous substances usually occurring in definite 
foci, though they may be quite diffuse. This condition 
may be associated with other diseases which tend to 
mask any specific symptoms. One case of amyloid 
change has been observed in a hog that clinically showed 
no manifestation of disease and was in prime condition 
at the time of slaughter. The amylaceous substance is 
insoluble, and the condition is therefore probably incur- 
able. 

Glycogenic Infiltration 

Glycogenic infiltration is a condition in Avhich excessive 
quantities of glycogen accumulate in the liver. This 
condition is observed occasionally in the liver of slaugh- 
tered swine. 



THE DIGESTIVE SYSTEM 59 

Etiology. — Disturbed carbohydrate metabolism is 
inseparably associated with glycogenic infiltration, al- 
though the specific relation of disturbed carbohydrate 
metabolism and glycogenic infiltration is not known. 
Inflammatory disturbances and tumor formation appear 
to have some relationship with glycogenic infiltration. 

Lesions. — A glycogenic infiltrated liver is pale, 
larger than normal, and of a putty consistency. 

Symptoms. — No definite symptoms are attributed 
to the excessive accumulation of glycogen in the liver. 
The condition may be suspected when the animals are 
sluggish and do not exercise, as it has been demonstrated 
that during muscular activity glycogen is used in con- 
siderable quantities and is drawn from the storehouse, 
which is the liver, as it is required. 

Treatment. — Regulation of diet and exercise is 
far more valuable than medicinal treatment. 

Gall-stones (Cholelithiasis) 

Gall-stones are accumulations of organic or inorganic 
substances in the various bile tubes or gall bladder. 
They are relatively common in swine. 

Etiology. — The presence of a substance that will 
act as a nucleus is the first step in the formation of a 
calculus. Precipitation of some of the bile ingredients 
is the second step in calculus formation, and the accumu- 
lation of the precipitate upon the nucleus completes 
the process. Bits of mucous or any particle of foreign 
matter may serve as a nucleus. Precipitation may be 
caused by supersaturation of the bile with inorganic 
salts, or it may be a sequel of fermentation of bile. In 
addition, bacteria and other factors may be causative 
agents of calculus formation. 

Lesions. — Cholelithiasis, or gall-stones, is found 
most frequently in the gall bladder. It may occur, 
however, in the hepatic duct or in anj^ of the collecting 
bile tubes, regardless of their size. The presence of 
gall-stones usually causes obstruction and distention of 
the gall bladder of the bile tubes in which they occur. 



60 SAVINE DISEASES 

If the obstruction has existed for some time, icterus will 
usually be more or less pronounced. 

Upon opening the gall bladder or bile ducts containing 
the calculi, thick grumose bile escapes and the con- 
crements or calculi are observed. Gall-stones may 
occur singly, but they are usually multiple. They are 
usually of a brownish-chocolate color and vary in size 
from mere specks to masses an inch or more in diameter. 
They may be round or any other shape, and when many 
are present they are usually faceted where they come 
into contact with each other. The gall-stones may be 
composed of organic material entirely and be quite soft 
or they may be incrusted with mineral matter and be 
quite hard. Upon sectioning them they are usually 
found to have been made up in layers, and it is not 
difficult to distinguish the nucleus. There is an inflam- 
mation of the mucous membrane of the gall bladder or 
affected bile tubes. 

Symptoms. — Very few if any cases of cholelithiasis 
have been recognized clinically. If the gall-stones 
obstruct the outflow of bile sufficiently there will be 
general icterus. There are probably some digestive 
disturbances also. 

Treatment. — The nature of this condition does not 
warrant treatment. 

Hyperemia 

Hyperemia of the liver may be physiologic or patho- 
logic. Physiologic hepatic hyperemia occurs after eating 
and is of no significance economically or pathologically. 
Pathologic hepatic hyperemia may be either venous 
(passive) or arterial (active). 

Passive hepatic hyperemia is caused by obstructed 
outflow of blood. Cardiac defects of the valves of the 
right side of the heart are a potent cause. Obstruction 
of the posterior vena cava or the hepatic vein by new 
growths, abscesses, and cicatricial tissue will also produce 
venous engorgement of the liver. 



THE DIGESTIVE SYSTEM 61 

Lesions. — A careful examination will disclose the 
lesion producing the engorgement as well as the engorged 
condition of the liver. The liver will be full of blood 
and of a slightly darker color than normal. If the con- 
dition becomes chronic there will be fibrous proliferation. 

Symptoms. — The signs of venous hepatic hyperemia 
vary according to the intensity of the condition and 
its duration. The animals become dull, and there is only 
a sluggish action of the bowels. If the condition pro- 
gresses until there is fibrous proliferation, disturbances of 
nutrition become evident. 

Arterial hepatic hyperemia may be the result of involve- 
ment of the hepatic artery or of the portal vein. This 
is a condition characterized by an increased inflow of 
blood into the liver. Hyperemia of the hepatic artery 
is not common, and when it does occur it is usually 
chronic. This condition is usually the result of partial 
occlusion of the gastric or splenic branches of the celiac 
axis, although it may be caused by some irritation in 
the terminal vessels in the hepatic interstitial tissue. 
No definite symptoms are evidenced, and the value of 
treatment is doubtful. 

Portal hepatic hyperemia is usually caused by tainted 
foods or by infection. The liver may be increased fifty 
per cent in volume, and becomes gorged with blood. 
The symptoms are obscure. Some relief may be obtained 
by the free use of laxatives. 

Treatment. — The removal of the cause, if that be 
possible, is about all that can be accomplished. 

Hepatitis 

Inflammation of the liver, or hepatitis, is rather 
common in swine. The condition may assume either an 
acute or chronic form. Hepatitis as a rule is secondary to 
other disturbances, although it may occasionally be 
primary. The inflammatory process may affect the 
liver cells and is then designated parenchymatous hepatitis, 
or it may affect the supporting framework, when it 
is designated interstitial hepatitis. With but few excep- 



62 SWINE DISEASES 

tions hepatitis of swine has not been made a subject of 
special investigation^. 

Acute Parenchymatous Hepatitis 

Acute parenchymatous hepatitis is a destructive 
inflammation involving the liver cells. 

Etiology. — Chemic poisons derived from the bowel 
and carried to the liver by way of the portal vein is a 
frequent cause of this condition. Bacterial infection, 
entering the liver by way of the portal vein, hepatic 
artery, hepatic vein, umbilical vein, or hepatic duct is 
a common cause of hepatitis. The Distoma or liver 
flukes, the larval form of Stephanurus dentatum, and 
other parasites produce hepatitis. 

Lesions. — The liver becomes enlarged and loses its 
sharp outlines; it is darker in color, gorged with blood, 
and is more friable than the normal liver. There may 
be small hemorrhagic areas. 

Symptoms. — Icterus is usually the first and fre- 
quently the only evidence of the disease. The affected 
swine may show symptoms of pain when defecating or 
when moving about. 

Treatmient. — Laxatives may produce some relief. 
The proper diet should be given and the animals made 
comfortable. 

Suppurative Hepatitis 

Suppurative hepatitis as a primary condition is not 
very common in swine. 

Etiology. — This condition is, as a rule, the result of 
bacterial infection, although parasites of various kinds 
may produce it. The infection in the liver is usually 
secondary and metastatic. Pyogenic Staphylococci and 
Streptococci are the most common infecting agents, 

■^An enzootic hepatitis of young pigs occurred in Russia and was 
investigated by Semmer. This disease has also occurred in eastern 
Prussia, where it has been very fatal. The cause of this condition is 
probably a coccus which is thought to gain entrance into the umbilicus 
at the time of farrowing. The affected liver is enlarged, nodular and 
variegated in color. 



THE DIGESTIVE SYSTEM 63 

although the colon bacilli and its various derivatives 
have been identified in the pus from liver abscesses. 

Lesions. — The liver contains suppurative centers of 
varying dimensions. The foci may occur throughout 
the entire liver and be microscopic in size, causing a 
uniform enlargement of the liver, or the suppurative 
centers may be as large as walnuts and appear as small 
abscesses. The liver will be engorged with blood, more 
friable than normal, and it may be variegated in color, 
due to alternating small hemorrhagic areas and sup- 
purative foci. 

Larger suppurative centers are gray in color and may 
or may not be circumscribed by a capsule of fibrous 
tissue. The content may be semifluid pus or it may be 
caseous or even calcified. 

Symptoms. — The evidence of suppurative hepatitis 
consists of general depression. The animal does not 
move of its own volition. There is pain on palpation of 
the abdomen (if abdominal walls are not too thick), and 
icterus. Less extensive suppuration of the liver may 
not produce any distinct symptoms. 

Treatment. — The animal should be made as com- 
fortable as possible and the evacuation of the bowel 
content facilitated by the use of laxatives. 

Acute Interstitial Hepatitis 

Acute interstitial hepatitis is not a common con- 
dition but it does occur in swine and therefore should 
receive some consideration. 

Etiology.— The cause of acute interstitial hepatitis 
probably always enters the liver by way of the hepatic 
artery, and is most frequently due to bacterial infection 
or animal parasitic invasion. The various suppurative 
bacteria, Bacillus coli communis or some of its derivatives 
and Bacillus necrophorus, may be the causative agent. 
Protozoan parasites and the larvae of some vermes are 
responsible for some cases of acute interstitial hepatitis. 

Lesions. — The liver is enlarged and appears to be 
affected with chronic interstitial hepatitis because the 



64 SWINE DISEASES 

interlobular tissue is infiltrated with leukocytes. The 
liver tissue is soft and friable. Microscopic study of 
these livers has revealed the fact that in nearly every 
instance the infiltration leukocytes are practically all 
eosinophiles. 

Symptoms.^ — Few if any investigations of these 
cases have been made clinically or at least such have 
not been reported. The marked interlobular infiltration 
tends to obstruct the biliary capillaries, causing reab- 
sorption of bile with accompanying icterus. 

Treatment. — The nature of this condition permits 
of little if any relief by the use of drugs. Providing the 
proper diet and surroundings are provided, treating the 
symptoms as they arise is apparently all that can be 
advised for the relief of this condition. 

Chronic Interstitial Hepatitis (Cirrhosis -Sclerosis) 

Chronic interstitial hepatitis, cirrhosis or sclerosis of 
the liver, consists of a proliferation of fibrous tissue 
which damages and ultimately displaces some of the 
functional liver tissue. The condition is rather common, 
especially in swine fed upon fermented products, such 
as distillery waste, or garbage. 

Etiology. — This condition is due to injurious chemical 
agents derived either from the food or from bacterial 
action, that is, those substances that are capable of 
producing a mild degree of irritation. Animal para- 
sites, either by direct mechanical irritation or irritation 
by eliminated chemicals, also produce chronic inter- 
stitial hepatitis. The condition, too, may be secondary 
to other disease processes. 

Lesions. ^ — Chronic interstitial hepatitis is essentially 
a proliferation of fibrous tissue. The fibrous tissue may 
be produced within the liver lobule, causing an enlarge- 
ment of the lobules and also of the liver. This type is 
designated hypertrophic sclerosis of the liver. Such a 
liver is enlarged, dense, increased in weight, lighter in 
color, and when cut gives the impression of cutting 
fibrous tissue. In other instances the proliferation of 



THE DIGESTIVE SYSTEM 65 

fibrous tissue occurs in the interlobular tissue only. 
This newly formed fibrous tissue later contracts, thus 
diminishing the size of the affected lobules, and there- 
fore the liver as a whole. This condition is termed 
atrophic sclerosis. Such a liver usually has an irregular 
outline (hobnail liver) and is smaller, denser, and fighter 
in color than a normal liver. It is possible that hyper- 
trophic sclerosis, or the formation of new fibrous tissue 
throughout the entire liver lobule, follows when the irri- 
tant is introduced through the portal vein, and atrophic 
sclerosis occurs when the irritant is introduced through 
the hepatic artery. 

Symptoms. — Hepatic sclerosis has an insidious onset. 
Probably the first evidence of the disease is digestive 
derangement, which later may be accompanied by 
icterus. The animals become unthrifty and finally 
weak and emaciated. 

Treatmient. — Remove the cause and prevent further 
progress of the disease. A strict diet and the main- 
taining of a laxative condition of the bowel may permit 
the affected animals to be gotten into condition for 
slaughter. 

Tumors 

Hepatic tumors are frequently observed by veterinary 
inspectors in abattoirs, but these tumors are rarely of 
sufficient magnitude to have produced visible symptoms 
in the animal prior to slaughter. 

The various kinds of tumors that have been observed 
in the liver of swine are true to the type for the same 
tumors in other animals. The malignant tumors of the 
liver frequently are found to be secondary. Of the 
types of liver tumors the following have been identified, 
lipoma, myxoma, angioma, sarcoma, adenoma, epi- 
thelioma, and carcinoma. 

No definite symptoms of hepatic tumors can be 
described; often there is no outward evidence. There 
may be digestive disorders, emaciation, and evidence of 
malnutrition. 



66 SWINE DISEASES 

The treatment of hepatic tumors in swine is not 
practicable. 

Parasites 

Parasitic invasion of the Hver is very common in 
swine. The result of hepatic parasitism has not attracted 
the attention of the cHnician, but it has caused con- 
siderable concern with the inspectors o'f meat and food 
products. In the middle section of the United States 
the livers of the majority of swine evidence parasitism 
or lesions indicating previous parasitic invasion and 
activity. Parasitic conditions of the liver of swine are 
of considerable economic importance because of the con- 
demnation, and therefore the loss, of this organ as a 
food product. 

Coccidiosis 

Liver abscesses containing Coccidia have been ob- 
served. The conditions are not very common. Johne 
observed in swine abscesses as large as an apple that 
contained a Coccidium to which he attributed the 
cause. 

Stephanurosis 

It is rather common to observe lesions in the liver of 
swine caused by the Stephanurus dentatum. The mode 
of entrance of these parasites into the liver may be by 
way of the hepatic duct, through the portal vein, or by 
direct migration from the peritoneal cavity through the 
liver capsule. They establish inflammation accompanied 
by the formation of pus and later necrosis of the liver 
tissue. The entire lesion is surrounded by a rather 
dense white fibrous connective-tissue capsule. From 
one to three of the parasites are found in the necrotic 
purulent material. The content of the lesion later 
becomes caseous and may ultimately calcify. 

No symptoms have been observed in the liver that 
could be attributed to the direct action of the Stephanurus. 

Remedial treatment is not available, but preventive 
measures should be taken to avoid future disturbances. 



THE DIGESTIVE SYSTEM 67 

The exact life cycle of the parasite is not known, but 
general sanitary regulations are always in order and 
will no doubt be of value in preventing or at least dimin- 
ishing the extent of future infestations. 

Ascaridiasis 

An occasional ascarid migrates into the liver by way 
of the hepatic duct. These parasites in this location 
mechanically obstruct the outflow of bile and also pro- 
duce sufficient local irritation to establish a catarrhal 
inflammation of the hepatic duct, the gall bladder, or 
the bile duct. 

Icterus, associated with digestive derangement, will 
probably be the only evidence of the presence of this 
parasite in any portion of the liver or its excretory duct. 

The location of the parasite prohibits the successful 
use of therapeutic agents. The possibility of invasion 
into any of the hepatic structures may be diminished by 
frequent medication of the swine with agents previously 
mentioned that will eliminate these parasites from the 
bowel. Frequent cleaning, and removal of the excrement 
from the pens, yards, or barns, will tend to diminish 
infestation. 

Distomatosis 

This is a condition resulting from the invasion of the 
liver by the Distoma hepaticum, Distoma Americanum, 
or Distoma lanceclatum. All are commonly called flukes. 
Distomatosis occurs most frequently in animals kept 
upon low, marshy, or swampy lands. Swine raised in 
the southern part of the United States are commonly 
infested. The exact life cycle of these parasites has 
been carefully worked out and may be obtained by 
reference to works on parasites; suffice here to say that 
the ova are eliminated from the liver in the bile and 
pass to the outside in the fecal matter. Aiier several 
changes the embryos are found upon vegetation which 
is consumed by their hosts. They find their way up 
the hepatic duct and on into the bile tubes within the 
liver. 



68 SWINE DISEASES 

Lesions. — ^The lesions established by the different 
types of Distoma are slightly different. The Distoma 
hepaticum remains for six months in the bile tubes in 
the liver, where it produces obstruction of bile and inflam- 
mation of the bile tubes. The accumulated bile causes 
distention of the bile tube, which is usually very evident, 
particularly upon the posterior surface of the liver. The 
dilated bile tube is found to be thickened and contains 
thickened flocculent bile and flukes in some stage of 
development, depending upon the length of time after 
invasion that the autopsy is conducted. 

The Distoma Americanum either remains in the bile 
tubes or passes out into the substance of the liver, 
where it produces a cyst. These cysts, which attain 
the size of a hen's egg, are evidenced by grayish-black 
elevation upon the surface of the liver. The cysts 
contain a chocolate-colored fluid and one or more dis- 
tomes. 

The Distoma lanceolatum produces lesions similar to 
those produced by the Distoma Americanum. The 
latter parasite is easily distinguished from the former by 
its large size and its distinctive shape. 

A liver in which the Distoma have developed and 
disappeared contains cicatrices or areas of necrotic 
calcareous material, evidences of the parasitic invasion. 

Symptoms. — It is diflacult to diagnose hepatic 
distomiasis by the clinical symptoms. The history of 
the case, particularly the source of the animal affected, 
should be given proper consideration. The symptoms 
vary according to the intensity of infestation, and do 
not appear for from one to two months after infestation. 
There is more or less icterus, digestive derangement, 
unthriftiness, and emaciation. The disease may terminate 
fatally and it may be quite widespread, affecting a large 
percentage of swine in the Southern States, particularly 
during wet seasons. 

Treatment. — ^Treatment is of no avail. Invasion 
may be diminished or entirely prevented by keeping 
swine out of pens, yards, and pastures where previous 



THE DIGESTIVE SYSTEM 69 

infestation has occurred and by properly disposing of 
the excrements of swine that are infested. 

Ech inococcosis 

The invasion of the Hver of swine with the larvae of 
the Taenia echinococcus is quite common. In the Old 
World from one per cent to seventy per cent of the 
swine are reported to be so infested. 

The mode of entrance into the liver is by way of the 
portal system, the embryo passing through the intestine 
into capillaries that empty into radicles of the portal 
vein. Infestation is derived from food or drink con- 
taminated with the feces of dogs, that harbor the Taenia 
echinococcus. 

Lesions. — ^The liver is enlarged; the degree depending 
upon the number of parasitic cysts it contains. Gerard 
observed an infested swine liver that weighed 110 pounds. 
The surface of the liver may be very irregular due to 
the presence of the cysts near the capsule or just beneath 
the capsule. The cysts, which vary in size from a pear 
to a small hen's egg, are the primary lesions and may be 
polymorphous or multilocular. The polymorphous cysts 
are surrounded by a fibrous capsule inside of which the 
true cystic membrane is found and upon which daughter 
and granddaughter cysts and the head of the future 
tapeworm may be seen. The cyst contains a pale, 
straw-colored, limpid serum. The multilocular cyst is 
a mass of single cysts developing on the outside of the 
true cystic membrane instead of developing on the inside, 
as in the polymorphous cyst. The cysts necessarily dis- 
place and by pressure destroy liver tissue. Old cysts 
contain a cheesy or caseous substance; in some instances 
a purulent collection. 

Symptoms. — Clinical evidence of the presence of 
hepatic echinococcus cysts are usually wanting. A few 
cases of ascites associated with hepatic echinococcosis 
have been recorded. There may be icterus and some 
digestive disturbance. 



70 SWINE DISEASES 

Treatment. — Because of the location and nature of 
the lesion, treatment for echinococcosis is ineffectual. 
The condition is readily prevented by treating with 
teniafuges all valuable dogs that are associated in any 
way with the swine and by destroying all worthless 
curs and properly disposing of their carcasses. 

Cysticercosis 

Hepatic cysticercosis of swine is not very common. 
It is found principally in young pigs, where it is the 
result of invasion of the liver with embryos of the Tsenia 
marginata of the dog. These embryos are obtained 
in food that has been contaminated with dog feces. 
They gain entrance to the liver by way of the portal 
vein. Some of the embryos pass out of the liver in the 
hepatic vein; others bore through the organ and its 
capsule into the peritoneal cavity. 

Lesions. — In extensive invasion the liver is enlarged. 
There may be evidence of perihepatitis. A small elevation 
may occur upon the surface and in each elevation a 
small opening may be observed. The liver is of a varie- 
gated color, due to alternating areas of hemorrhage and 
degeneration. 

Symptoms. — Unthriftiness, weakness, anorexia, and 
increased thirst maj^ be observed in hepatic cystic- 
ercosis. The affected animals may become rapidly 
emaciated; there may be evidence of peritonitis — and in 
exceptional cases the animals may die suddenly, but as 
a rule they linger for several weeks. 

Treatment. — Symptomatic treatment may be re- 
sorted to, but it is doubtful if satisfactory results will be 
obtained. This condition may be prevented by the proper 
treatment or disposal of dogs as recommended under 
echinococcosis. 

PANCREAS 

Little is known concerning the diseases of the pan- 
creas. A condition known as multiple fatty necrosis 
occurs in swine and is thought to be the result of obstruc- 



THE DIGESTIVE SYSTEM 71 

tion to the outflow of pancreatic juice. Sarcomas 
involving the pancreas in swine have been observed, 
but they were evidently not primary in that organ. 

PERITONEUM 

Defects in the formation of the peritoneum are not 
common. Rarely cystic inclusions or exclusions may be 
observed. 

Injuries 

The peritoneum is occasionally injured in swine. 
The injuries may be inflicted during a surgical operation 
or they may be produced accidentally. The result of 
injury of the peritoneum varies with the location and 
the extent and nature of the injury; which may consist 
of a bruise of the peritoneum, in which case there is a 
local inflammatory disturbance; a puncture of the peri- 
toneum, resulting in general peritonitis; or a laceration 
of the peritoneum, permitting eventration. 

The results of violence from the external surface are 
self-evident, but the injuries may be inflicted by foreign 
bodies in the alimentary canal. In such cases there is 
more or less of digestive derangement and local or general 
peritonitis. 

Treatment. — ^Medicinal treatment may be applicable 
when the peritoneum is intact, but in lacerations of the 
peritoneum surgical interference alone is of value. 

Ascites 

iVscites is a condition resulting from the accumulation 
and retention of excessive quantities of lymph or diluted 
lymph in the peritoneal cavity. The peritoneal cavity 
is in reality a large lymph space. 

Ascites is very rare in swine. 

Etiology. — Ascites is caused by an excessive out- 
pouring of lymph into or a diminished absorption of 
lymph from the peritoneal cavity. The lymph escapes 
from the blood capillaries in the subserosa on to the 
surface of the peritoneum. The usual causes are 



72 SWINE DISEASES 

obstructed portal circulation, which may be due to 
disturbances of the liver, valvular defects of the heart, 
chronic nephritis, or direct pressure upon the portal 
vein. 

Lesions. — Enlarged abdomen, due to the accumulated 
fluid in the peritoneal cavity. The fluid is thin, limpid, 
and is noncoagulable. The lesions of the primary cause 
may also be observed. 

Symptoms. — A pendulous abdomen associated with 
digestive disturbances and malnutrition are the principal 
evidences of this disease. 

Treatment.- — Treatment is of little value. Tem- 
porary relief may be obtained by paracentesis abdominis. 

Peritonitis 

Inflammation of the peritoneum is not of as common 
occurrence in swine as it is in horses, and the disease is 
less fatal in swine than it is in most other animals. 

Etiology. — Injuries, and infection following par- 
turition, are the most common causes of porcine peri- 
tonitis. Occasionally an ascarid may perforate the bowel 
and establish inflammation. 

Lesions. — Peritonitis may be serous, fibrinous, hemor- 
rhagic, purulent, septic, or tubercular; local or general; 
acute or chronic. The lesions will vary according to 
the type of inflammation. There is first tumefaction, 
congestion, loss of gloss of surface, and exudation. The 
serous exudate is sticky, serum-like, and may be tinged 
with blood; the fibrinous exudate coagulates and causes 
adhesions ; the hemorrhagic exudate is of a bloody appear- 
ance; and the purulent exudate is composed of pus. 
Septic peritonitis is associated with the accumulation of 
a putrid material upon the peritoneal surface. There 
may also be evidence of injury, or metritis, and probably 
some intestinal content in the peritoneal cavity. Chronic 
peritonitis is associated with the proliferation of fibrous 
tissue and usually greater or less adhesions of the visceral 
and parietal peritoneum. 



THE DIGESTIVE SYSTEM 73 

Symptoms. — ^Acute peritonitis is associated with 
abdominal pain, the severity of which depends upon the 
extent and intensity of the inflammation. The pain may 
be manifested on palpation of the abdomen. The 
affected animals have a "tucked up'* appearance; the 
appetite is diminished or perhaps wanting. There is a 
rise of temperature and a rapid, wiry pulse. The animals 
are uneasy and restless. 

Animals affected with chronic peritonitis may show 
some digestive derangement or there may be no evidence 
of disease. 

Treatmient. — Remove the cause, and the further 
treatment will depend upon the cause and nature of the 
lesions. In all cases the bowel movement should be 
diminished or inhibited by the use of opiates. If the 
disease is the result of injury, surgical interference and 
the rational application of antiseptics is indicated. If 
the animals eat they should receive only liquid foods 
easy of digestion. 

Tumors 

Some cases of peritoneal tumors in swine have been 
reported. The fibroma of swine is usually benign; it 
may be tabular or pedunculated. Sarcoma, endothe- 
lioma, and carcinoma also have been observed, the first 
being the most common. 

The above-mentioned tumors are pathologically iden- 
tical to the same type of tumors observed elsewhere in 
swine or in other animals, and they produce practically 
the same results, with the possible exception that the 
malignant tumors are not so fatal as in some other 
animals, particularly in the human. 

Parasites 

The cystic form of the Taenia echinococcus (echin- 
ococcosis) is probably the most common parasitic invader 
of the peritoneum of swine. The description of these 
cysts will be found under the consideration of parasites 
of the liver. 



74 SWINE DISEASES 

The Cysticercus tenuicollis is occasionally observed 
involving the peritoneum of swine, although in the 
central United States these cysts are much more common 
in sheep. These cysts contain only one tapeworm 
embryo, differing in this particular from the cysts of 
the Taenia echinococcus. They have a double membrane, 
the embryo is suspended in a thin, watery fluid that fills 
the cyst, which may attain the size of an English walnut. 

Stephanurus dentatum, both in the adult and larval 
stage, may be found in relation to the peritoneum. The 
lesions they produce in the peritoneum are the same as 
those produced by this parasite elsewhere in the body. 

The Ascaris suum may bore through the intestine and be 
found in the peritoneal cavity. As they pass out of the 
intestine they carry various bacteria with them and pos- 
sibly also permit the escape of some intestinal content 
which is always teeming with bacteria. Thus infectious, 
usually septic, peritonitis results. 



SECTION II 



THE RESPIRATORY SYSTEM 



NOSE 

THE habit of rooting predisposes the snout of swine 
to various kinds of injury regardless of the fact 
that this organ has been designed for such pur- 
poses. Ringing of swine produces an injury that in 
some instances is difficult to correct. 

Epistaxis 

Nose bleeding is not a disease primarily, but is usually 
a symptom of some other disease or abnormal condition. 
Epistaxis occurs rather commonly in swine. 

Etiology. — True epistaxis is a result of the escape of 
blood from some of the blood vessels of the nasal chambers 
or related cavities. It is a very common symptom in 
hog cholera and swine plague, and has been observed 
in cases of anthrax. The condition is sometimes asso- 
ciated with ulceration of the schneiderian membrane 
regardless of the cause of the ulcers. In some instances, 
it may be due to mechanical injuries of the mucous 
membrane. 

Lesions. — Except in epistaxis resulting from trauma, 
the lesions of the primary condition are more prominent 
than those associated with the hemorrhage. 

Symptoms.— Escape of blood, usually from the 
nostril, is the principal evidence of epistaxis. The 
escaping blood may be scarlet red or dark red, depending 
upon whether the blood is escaping from an artery or a 
vein. Epistaxis can be distinguished from pulmonary 
hemorrhage by the fact that the discharged blood from 
the latter is frothy. 

75 



76 ' SWINE DISEASES 

Treatment. — Epistaxis is usually not fatal. It is 
difficult to treat in swine because of the small size of the 
opening of the nostril. Hydrogen peroxide may be 
introduced by means of a syringe, and this gives immediate 
and sometimes permanent relief. A solution of adrenalin 
chlorid gives similar results. 

Rhinitis 

Catarrhal rhinitis is very common in swine. It may 
be either acute or chronic. 

Etiology. — Catarrhal inflammation of the schneid- 
erian membrane is most commonly caused by the inhala- 
tion of dust or other irritating substances. It may be 
caused also by sudden temperature changes. It is 
sometimes associated with other disease conditions, 
particularly swine plague and hog cholera. An infec- 
tious type of this disease has been identified and is 
discussed separately. (See p. 77.) 

Lesions. — Acute catarrhal inflammation of the nasal 
mucosa is characterized by congestion and tumefaction 
of the mucous membrane. This membrane is at first 
dry, but later varying quantities of a serous fluid and 
mucous escape upon the surface of the mucosa and are 
discharged, some of the discharge accumulating upon 
the external surface of the nostril. The exudate may 
become infected and invaded by leukocytes, the dis- 
charge thus becoming mucopurulent or purulent. Chronic 
catarrhal inflammation may produce a hypertrophy or 
atrophy of the nasal mucosa. The hypertrophic change 
is due to the production of large quantities of fibrous 
tissue in the submucosa. The mucosa thus becomes 
thickened, dense, and leathery. The increased volume 
of the mucous membrane may so diminish the cavities of 
the nose that breathing is difficult. In other instances 
the mucous membrane atrophies, the nasal cavity thus 
becoming larger. It is not unusual to find desiccated 
discharges adhering to the mucosa. In either the hyper- 
trophic or atrophic forms of chronic catarrhal rhinitis 
there may be ulceration of the mucous membrane. When 



THE RESPIRATORY SYSTEM 77 

such ulcers occur they usually involve only the mucous 
membrane. 

Symptoms. — Discharge from the nose of a serous, 
mucous, seromucous, pus, or mucopurulent material is 
indicative of nasal catarrh. The affected animal may 
sneeze and evidence some dijQ&culty in breathing. 

Treatment. — Remove the cause, and if the condition 
has not persisted until it is chronic there will usually be a 
speedy recovery. A common cause of catarrhal rhinitis is 
inhalation of dust, and therefore dusty pens frequently 
contain swine with nasal catarrh. The condition in such 
cases can usually be checked by sprinkling or wetting 
the pens. Medicinal treatment is not of great value for 
this condition in swine because of the difficulty of its 
application. Laxatives may be of some value. Those 
animals affected with advanced cases of the chronic 
form of the disease had best be put into a marketable 
condition, if possible, and sold for slaughter. 

Infectious Nasal Catarrh 

An infectious nasal catarrh of swine occurs enzootically 
in Germany It usually confines its ravages to pigs less 
than six months of age. A similar clinical affection 
occurs in some sections of the United States, but in this 
country the specific causative agent has not been identi- 
fied. 

Etiology. — In 1906, the Bacillus pyocyaneus was 
identified by Koske as the causative factor, although the 
infectious nature of the disease was recognized as early as 
1890. The Bacillus pyocyaneus is found in manure 
heaps and mulched soils; it gains entrance to the nose 
while the swine are rooting and is readily transmitted 
from a diseased to a healthy animal by means of the 
nasal discharges. 

Lesions. — This disease is characterized by an intense 
inflammation which causes a marked congestion of the 
mucosa and not infrequently a hemorrhagic inflammation. 
The lesions extend and involve the sinuses and the 
ethmoidal cells, and there may be involvement of the 



78 SWINE DISEASES 

optic and olfactory nerves, of the cerebral meninges, and 
of the brain itself. The usual lesions in the last-mentioned 
structures consist of hemorrhages beneath the sheath of 
the optic and olfactory nerves, congestion of the meninges, 
and edema of the cerebral tissue proper. Various changes 
may be observed in other internal organs as a result of 
high temperature and possibly also of metastasis of the 
infecting agent. 

Symptoms. — High temperature and inappetence are 
usually the first symptoms of the disease. Sneezing, 
and vigorous rooting or rubbing the nose, are followed by 
epistaxis, edema of the snout, and difficult breathing. 
The affected animals may be blind in one or both eyes, 
and if there is meningeal involvements the pigs will 
evidence extreme excitement and finally die in a comatose 
state. The disease may result fatally in a very short 
time, its course in the most fatal epizootics being from 
three to six days. A chronic or less fatal form has been 
observed in which the course of the disease varies from 
one week to several weeks, and some of the animals may 
recover. 

Treatment. — In the acute form of infectious nasal 
catarrh treatment has not been successful. From the 
experience of those veterinarians where this disease pre- 
vails it seems best to recommend destruction of all affected 
animals. An antitoxin may be prepared and used to 
offset the injurious influences of the toxic substances 
produced and eliminated by the Bacillus pyocyaneus. 
Prophjdactic sanitary measures should be instituted and 
rigidly enforced on premises where this disease abounds. 

Tumors 

Various tumors have been observed in the nasal 
cavity of swine or involving some related structure. 
Almost all of these tumors have been of the benign type 
and therefore interfere only mechanically. Pedunculated 
fibromas are not so common in swine as in some other 
animals. 



THE RESPIRATORY SYSTEM 79 

LARYNX 

Laryngitis 

Inflammatory disturbances of the larynx are relatively 
common in swine but are not of sufficient gravity to 
warrant a lengthy discussion. 

Etiology. — Undue exposure and inhalation of sus- 
pended or gaseous irritants are common causes of laryn- 
gitis. In swine, as in other animals, laryngitis is rarely 
a distinct process but is a condition associated with 
inflammatory disturbances of the pharynx, or trachea, 
and therefore the inflammatory process of the larynx is 
frequently an extension from an adjacent structure. 
Chronic laryngitis results from the same causative factors 
as the acute type, being merely extended over a longer 
period. 

Lesions. — Laryngitis in swine is generally of a 
catarrhal type and may be either acute or chronic, al- 
though an occasional case of croupous laryngitis occurs. 
The lesions observed are practically identical with the 
usual lesions of this type of inflammation. 

Symptoms. — The principal symptom of laryngitis is 
a cough, which is at first dry, later moist, and always 
painful. The cough may become convulsive. In the 
intense acute attacks there will be rise of temperature 
and probably inappetence. By palpation the laryngeal 
region will be found supersensitive. 

Treatment. — Provide sanitary surroundings and if 
the patient is inchned to eat, give sparingly of easily 
digested slops. Medicinal treatment is so difficult to 
apply that frequently more harm than good is the result. 

Tumors 

Laryngeal tumors are rare. However, pedunculated 
fibromas have been observed, and epithelioma has been 
reported. 



80 SWINE DISEASES 

TRACHEA 

Malformations 

A case occurs occasionally in which the esophagus 
forms a union with the trachea. Pigs so affected usually 
die soon after farrowing. 

Stenosis 

Congenital stenosis may occur in swine, but is rela- 
tively rare. Acquired stenosis is also rare, because of 
the protection of the trachea from external injuries. 

Tracheitis 

This inflammatory disturbance is usually associated 
with laryngitis or bronchitis, and partakes so closely of 
the nature of these latter affections that further descrip- 
tion will not be given. 

Tumors 

Tracheal tumors are not common in swine, though 
fibromas and myxomas of the benign tumors have been 
observed. 

BRONCHIAL TUBES 

The principal malformations of the bronchial tubes 
consists of an irregularity in the distribution of the 
branches of those tubes, but as a rule this produces little 
or no inconvenience to the animal and is therefore of 
scientific interest only. 

Stenosis 

Bronchial stenosis is relatively common in swine. 
The condition may affect either the large or small tubes. 
Bronchial stenosis is probably most frequently the result 
of a diseased condition of the bronchial mucosa, such as 
catarrhal inflammation, ulceration, tuberculosis, para- 
sitic invasion, or mechanical injury due to some foreign 
body, as a needle or a nail. 



THE RESPIRATORY SYSTEM 81 

Bronchitis 

The principal inflammatory disturbance of the 
bronchial tubes is of a catarrhal nature, at least in the 
beginning. Catarrhal bronchitis may be either acute or 
chronic. 

Etiology. — Undue exposure to inclement weather is 
one of the principal causes of bronchitis. Inhalation of 
dust-laden air is also an important causative factor of 
inflammation of the bronchial tubes. Infection is in 
many instances an auxiliary of other causes and the 
Bacilli necrophorous and pyocyaneus are many times the 
primary causes of bronchial catarrh. This condition may 
be associated with other diseases, such as swine plague 
or hog cholera. 

Chronic bronchial catarrh results from the action of 
the same causative factors that produce acute catarrh, 
but the irritants are usually less intense and act for a 
longer time. 

Lesions. — There is congestion of the affected mucosa, 
which later becomes covered with mucous or with a 
mucopurulent discharge. In extreme cases the discharge 
may be tinged with blood and become purulent. When 
the disease process involves the capillary bronchial tubes 
there is usually more or less of emphysema, due to obstruc- 
tion of the tubes with exudate which prevents the escape 
of air from the air cells. There may be areas of 
atelectasis which project beyond the surface of the lung 
and are of a darker color than the lung. 

Chronic bronchial catarrh is characterized by the 
presence of mucous, purulent, or even caseous material 
in the bronchial tubes, and by fibrous proliferation in 
the submucosa which may result in an attenuation of 
the mucosa. Dilatation or bronchiectasis is a common 
lesion, particularly in the dependent parts of the lung, in 
chronic catarrhal bronchitis. In long-standing cases 
there may be peribronchitis, evidenced by fibrous pro- 
liferation around the bronchial tubes, which may extend 
into the pulmonary tissue. 



82 SWINE DISEASES 

Symptoms. — The principal symptom of bronchitis 
is a cough which in the beginning is dry but later becomes 
moist. The cough may become convulsive. As the 
disease progresses a nasal discharge becomes evident, 
which is at first of the nature of mucus but later becomes 
mucopurulent or purulent. Rales may be detected in 
thin swine, or possibly in any of the bacon breeds, but the 
chest wall of other swine is usually so thick that it prac- 
tically prohibits the recognition of pulmonary conditions. 
There is usually some rise of temperature in the beginning, 
but this may subside. The appetite may be diminished. 

Treatment. — Removing the cause and providing 
sanitary surroundings . will probably do more than 
medication to relieve this condition. Supply easily 
digested foods. If the swine can be controlled easily and 
placed in a piggery that can be made practically airtight, 
the animals may be successfully treated with medicated 
vapors, using such agents as oil of eucalyptus. 

Verminous Bronchitis and Pneumonia 

Verminous bronchitis is very common in swine in the 
United States; however, the infestation is only rarely of 
sufficient extent to produce serious damage. The lungs 
from a thousand swine were inspected in a Kansas City 
abattoir and sixty per cent of them contained pulmonary 
Strongyli in such numbers that the lesions could readily 
be observed by gross examination. 

Etiology. — Metastrongylus apri is the causative 
parasite of porcine pulmonary strongylosis. It is a 
white or brownish-white thread-like worm from one inch 
to one and a half inches in length. The adults inhabit 
the middle-sized and small bronchioles, usually in the 
posterior superior part of the lung, although they may be 
found elsewhere in the lung. The ova are carried out 
from the lung in the discharge and may pass out directly 
or pass into the pharynx and be eliminated in the feces. 
The exact life cycle is not known, but it is probable that 
the ova hatch and undergo several moults before regaining 
the animal body. The parasites gain entrance to the 



THE RESPIRATORY SYSTEM 83 

animal body in the food or water, infestation of swine 
being easily accomplished. Young pigs are most sus- 
ceptible; however, the parasites have been identified in 
swine of all ages. After the parasites gain entrance to 
the animal body they begin to migrate, some of them 
ultimately reaching the bronchial tubes. The exact 
route of migration is still a disputed question, but they 
pass either by way of the pharynx through the larynx 
to the bronchial tubes, by way of the blood stream, or 
directly through the tissues. 

Lesions. — ^The principal lesions in swine are found 
in the posterior lobes and in the superior part of those 
lobes. At first the lesions are confined to centers, or 
foci, which are cone-shaped and usually atelectatic, 
though they may protrude and be of a doughy con- 
sistency. In a later stage these foci are found to contain 
mucopurulent, purulent, or even caseous substances in 
varying quantities in addition to from one to many 
Strongyli and their ova. Similar discharges will be 
found in the bronchial tubes and even in the trachea, 
and occasionally disintegrated vermes and their ova will 
be found in the expectorate. There may be bronchiec- 
tasis, but this condition is not common. The visceral 
pleura may show evidence of chronic inflammation. 

Symptoms. — The period of incubation varies from 
four to eight weeks. Although this condition is very 
prevalent, the infestation is usually limited and fatalities 
from this disease are exceptional. The primary symptom 
IS a cough, which usually involves several animals at once 
and becomes more frequent as the disease progresses. 
In fatal or severe cases the cough is paroxysmal, the 
animals sometimes falling to the ground from exhaustion 
and lack of air. A sticky, adhesive discharge prevails 
and accumulates upon the nostrils, respiration becomes 
difficult, and a distinct wheezing sound can be heard. 
The temperature may be increased from one to three 
degrees Fahrenheit. Emaciation is rapid. Edema of 
the dependent parts occurs, and the animals become 
weak and finally die of exhaustion. The course of the 



84 SWINE DISEASES 

disease varies from one to three or four months. The 
diagnosis should be based upon the history of the out- 
break, the number of animals involved, the character of 
the cough, and finally upon the detection of ova and 
parasites in the discharges and the presence of parasites 
in the lungs on autopsy. 

Treatment. — This disease is difficult to treat because 
of the location of the parasites and the difficulty of con- 
trolling swine. The only rational method consists of 
the intratracheal injections of some agent that will 
destroy the parasites, or by the inhalation of medicated 
vapors. These methods are not easily adapted to the 
treatment of swine, particularly the intratracheal injec- 
tions. Medicated vapors may be used, providing the 
swine can be confined in an airtight room. 

Further infestation should be prevented by the proper 
disposal of the various excretions from the infested 
animals. The pens should be thoroughly" cleaned and 
some efficient parasiticide applied. If the infestation is 
in pasture land, it will be necessarj^ to change pasture, 
keeping all swine away from the known infested pasture 
for at least a year, and for two years if possible. 

LUNGS 

Atelectasis 

This is a condition of collapse of the lung; the 
absence of air in the lung, and may be either congenital 
or acquired. The lung of the fetus is always atelectic 
before birth. This is one means of determining a still 
birth, and is often useful as evidence in legal cases. 
Partial congenital atelectasis may be the result of obstruc- 
tion of a bronchus with meconium or mucus; it may also 
be the result of excessive extrathoracic pressure. Acquired 
atelectasis may be due to compression of the lung by 
inflammatory exudate (pleuritic effusions), edematous 
transudate, or forward displacement of the diaphragm. 
It may also be due to obstruction of the bronchus, the 



THE RESPIRATORY SYSTEM 85 

air contained in the air cells being absorbed and per- 
mitting them to collapse. 

Lesions. — The affected lung tissue collapses and does 
not crepitate. It is red or reddish-brown in color, feels 
dry, is tough, and sinks in water. If the condition is 
of long standing, the affected area becomes darker in 
color and is designated cornification. In some instances 
the atelectic areas become spleen-like, due to the develop- 
ment of fibrous tissues, and this is termed splenization. 

Atelectasis diminishes the breathing capacity, which 
is the only symptom characterizing the condition. Small 
areas of the lung will not produce visible symptoms. 
This condition is usually associated with other disease 
processes, the symptoms of w^hich mask those of atelec- 
tasis. 

Atelectasis occurs in the lung of swine as a result of 
swine plague, hog cholera, bronchitis, pneumonia, and 
pleurisy, as well as of other less important diseases. 

Emphysema 

Pulmonary emphysema has been observed in swine 
but is not of common occurrence. It is due to con- 
ditions that favor the inflation of the lung with excessive 
quantities of air. Bronchopneumonia is occasionally 
associated with emphysema. The affected areas are 
soft, spongy, anemic, and project beyond the surface of 
the lung. 

Edema 

Pulmonary edema is not common in swine kept under 
ordinary conditions, but it is often found in those that 
are hyperimmunized for the production of anti-hog- 
cholera serum. Those having experience as serum pro- 
ducers occasionally have a swine die of pulmonary 
edema at the time or immediately after the intravenous 
injection of quantities of virulent blood. 

In comparison to their size, swine have a relatively 
small lung. The virulent blood that is used in hyper- 
immunizing is defibrinated but contains both the red and 



86 SWINE DISEASES 

white blood cells, some of which are disintegrated. Large 
quantities of this defibrinated blood, containing cor- 
puscles in various stages of disintegration as well as the 
virus, are introduced into an ear vein. The first capillary 
system it would pass through is in the lung where, no 
doubt, more or less obstruction of capillaries is effected 
and the virus, or some chemical ingredient of the blood, 
may cause an increased permeability of the blood vessels 
and facilitate the outpouring of the serum. 

Lesion. — The lungs are engorged with blood. The 
air cells contain varying quantities of serum, the lung 
thus becoming soggy and edematous. No other lesion 
of any significance is found. 

Symptoms. — The affected animal at first becomes 
restless and uneasy. There is increased respiration, 
soon followed by dyspnea, cessation of breathing, and 
death. In some cases all these symptoms occur within 
a few minutes and during the time that the virus is being 
introduced. If the injection is stopped instantly when 
the first symptom becomes evident some of the affected 
swine will recover, but in some of them the various 
symptoms occur, succeeded by death, even though the 
introduction of virus be stopped when the first symptom 
appears. An occasional case occurs where the swine 
will show no discomfiture at the time of the injection of 
the virus, but may be found in distress from a few minutes 
to an hour later. In such cases, death will usually 
result. 

Treatment. — Thus far no treatment has been found 
that appears to be of value. It is possible that centri- 
fuging the virus will overcome the difficulty. 

Hemorrhage 

Pulmonary hemorrhage is not common in swine as 
a primary disease. It has been reported as occurring in 
fattened swine that are driven to market, especially 
when they become very hot. It is rather common as a 
secondary condition in acute cases of pneumonia, swine 
plague, and hog cholera. 



THE RESPIRATORY SYSTEM 87 

Cause. — Engorgement of the lung capillaries, due to 
overexertion, excessive heat, or disease, is the chief 
cause of hemorrhage. Weakening of the vessel walls 
due to malnutrition, which occurs in some infective 
diseases, is another cause. 

Lesions. — Almost all cases of hemorrhage of the 
air passages posterior to the larynx are designated 
hemoptysis, or pulmonary hemorrhage, and it is difficult 
in some instances to differentiate tracheal or bronchial 
hemorrhage from pulmonary hemorrhage. If the hemor- 
rhage is primary the escaped and escaping blood is 
practically all that will be observed. The blood that 
escapes from the lung or smaller bronchial tubes will 
contain more entangled air, that is, be more frothy than 
that coming from the large bronchi and the trachea. 
In secondary pulmonary hemorrhage the lesions of the 
primary disease will also be evident. 

Symptoms. — If the extra vasate is limited in quantity 
it may be absorbed and no visible symptoms become 
evident. Escape of frothy blood from the nose and 
mouth characterizes hemoptysis. In cases where there 
are large quantities of blood escaping there will be more 
or less bronchial obstruction and consequently difficult 
breathing, and the animal may become weak from loss 
of blood. The condition may terminate fatally or the 
affected animal, in those cases where the hemorrhage is 
limited, may recover. 

Treatment. — Keep the affected animals cool, and 
where they will be least excited. 

Pneumonia 

Inflammation of the lung is not of common occurrence 
in swine as a primary condition but it is frequently 
associated with some other disease. 

Practically all types of pneumonia based upon patho- 
logic classification occur in swine. The following types 
will be described: catarrhal, croupous, purulent, and 
gangrenous. 



88 SWINE DISEASES 

Catarrhal Pneumonia 

Catarrhal pneumonia is a lobular involvement char- 
acterized by occlusion of the air cells, with exudate and 
desquamated epithelium. 

Etiology. — Catarrhal pneumonia is practically always 
a sequel of bronchitis and is therefore produced by the 
same causative factors. Bacillus pyocyaneus may cause 
catarrhal pneumonia. Catarrhal pneumonia is one of 
the characteristic lesions of swine plague due to the 
Bacterium suisepticus. (Description will be found in 
Chapter VIII.) Bronchopneumonia is occasionally sec- 
ondary to other diseases, such as hog cholera or septi- 
cemia. 

Lesions. — The inflammatory process is confined to 
a lobule or a group of lobules. As the disease progresses, 
other adjacent lobules may become involved, the affected 
areas thus becoming confluent and larger. In the 
beginning the affected areas are hyperemic. The alveoli 
soon become filled with inflammatory exudate which is 
at first fluid but later coagulates and becomes dry, the 
diseased lobules thus becoming solid. These areas are 
first red in color, but early become brown, gray, then 
yellow or yellowish-white, and if the condition persists 
abscess formation may occur. Bronchitis is usually 
associated with bronchopneumonia and in such cases the 
lesions characterizing bronchitis would also be present. 

Symptoms. ^ — Catarrhal pneumonia in swine is ex- 
tremely difficult to differentiate from bronchitis because 
of the inability to efficiently auscultate or percuss the 
thorax. Catarrhal pneumonia offers the same general 
symptoms that have been noted in bronchitis, except 
that pneumonic symptoms are usually more intensive 
than those of bronchitis. Catarrhal pneumonia has no 
definite course, the length or duration of the disease 
depending upon the cause, extent of the disease, and the 
resistance of the affected animal. The disease is most 
fatal in young swine. 

Treatment. — Medicinal treatment other than in- 
halation of medicated vapors is of little or no value. 



THE RESPIRATORY SYSTEM 89 

Proper sanitary conditions should be provided, and the 
affected animals should be given easily digested, whole- 
some food in suflBcient quantities to build up the body 
and maintain strength. If the causative factor is an 
infection, isolation and proper quarantine regulations 
should be enforced. 

Croupous Pneumonia 

Croupous pneumonia is a disease involving lobes or 
large lung areas and is characterized by the presence of 
a hemorrhagic exudate in the air cells. It is not a common 
primary condition in swine, but is frequently associated 
with hog cholera. 

Etiology. — Many predisposing factors enter into the 
causation of this disease, such as undue exposure or 
inhalation of irritating gases, but it is probable that the- 
specific active cause is microbian. 

Lesions. — Croupous pneumonia is characterized by 
the regularity of the successive changes that occur in the 
affected portion of the lung. The disease usually involves 
the dependent part of the lung and is essentially lobar, 
but more or less than this amount of lung may be involved. 
The various stages that occur in the lung are as follows: 
congestion, red hepatization, gray hepatization, and 
resolution. These stages occur in the order mentioned, 
and there is no distinct line of demarcation between 
each succeeding stage. The length of duration of each 
stage is subject to variation, but on the whole is quite 
constant. The congestive stage is of about twenty-four 
hours' duration. During this stage the affected portion 
of the lung is engorged with blood. In the beginning 
the air cells contain air but as the disease progresses 
the alveolar capillaries begin to leak or there is a hemor- 
rhagic exudate into the alveoli. Red hepatization begins 
when exudation is evident, and this stage persists for 
from three to five days; the area affected is red, dense, 
heavy, and liver-like. Gray hepatization is characterized 
by a gray or yellow coloration of the affected lung. This 
gtage succeeds red hepatization and is due in part to the 



90 SWINE DISEASES 

substitution of leukocytes for the coagulated hemorrhagic 
exudate that characterizes red hepatization and in part 
to chemical change of the hemoglobin of the extravasated 
red blood cells in the hemorrhagic exudate. The lung 
tissue affected with gray hepatization is gray in color, 
dense, heavy, and cuts like liver tissue. Gray hepatiza- 
tion persists for from three to five days, and when the 
alveoli are relatively free of exudate and leukocytes the 
lung is said to be in a stage of resolution, which includes 
that period of time during which the air cells are freed of 
all inflammatdry products and return to the normal 
condition. This is a variable period and depends upon 
the resistance of the affected animals. The lung, during 
this stage, contains some inflammatory products in the 
beginning and later small quantities of mucous and 
debris, but in the final stages the lung is practically 
normal. 

Symptoms. — Inappetence, high temperature, and 
increased respiration and heart action characterize 
croupous pneumonia. On the second or third day a 
"prune-juice" nasal discharge may be observed which 
later becomes mucous or mucopurulent. The affected 
swine are dull, listless, and will probably cough more or 
less when agitated. 

Treatment. — Sanitary surroundings, good water to 
drink, and an abundance of fresh air without drafts are 
prerequisites in the treatment of pneumonia. Laxatives 
should be given to prevent constipation. Heart stimu- 
lants may be required, but should not be administered 
except when necessary, as indicated by a rapid, weak 
pulse. 

Purulent Pneumonia 

Purulent pneumonia is an inflammation of the lung 
characterized by the formation of pus. This condition 
is relatively common in young pigs, although it may 
occur in swine of any age. 

Etiology. — Purulent pneumonia is of bacterial origin. 
The pyogenic Micrococci, Bacillus pyocyaneus, and 



THE RESPIRATORY SYSTEM 91 

tubercle bacillus are the most frequent causative factors 
of this condition. These organisms may be inhaled 
direct but they are more frequently introduced into the 
lung from elsewhere as emboli. Purulent pneumonia in 
old swine is therefore frequently associated with pyemia, 
abscess formation, or purulent metritis. Several cases 
have been observed in the carcasses of swine that had 
previously been hyperimmunized intramuscularly for the 
production of anti-hog-cholera serum. 

Lesions. — ^The principal lesion is suppuration, the 
centers of which vary in size and number but in the 
beginning are relatively small and in the earlier stages are 
not encapsulated but are surrounded by a zone of lung 
tissue intensely infiltrated with cells. As the condition 
progresses a circumscribing capsule is formed and the 
pus becomes thicker, and if the capsule is not destroyed 
the contained pus becomes caseous and may later become 
calcified. Should the capsule of a suppurative center 
become eroded the contained pus may infiltrate the 
adjacent lung tissue or discharge into a bronchial tube, 
the original suppurative center thus becoming a cavity. 
The pleura covering superficial suppurative centers 
usually shows some involvement. 

Symptoms. — The evidence of purulent pneumonia 
varies according to the nature and extent of the lesions. 
The presence of a single abscess may not cause any 
noticeable symptoms. General embolic purulent pneu- 
monia is characterized by intense symptoms consisting of 
chills, fever, difficult and hurried breathing, uneasiness, 
and general distress. The discharge of pus within the 
lung tissue is evidenced by rise of temperature and the 
associated cardiac and respiratory disturbances. 

Treatment. — No special line of treatment is of 
value. The animals should be placed in good quarters 
and cared for properly. 

Septic or Gangrenous Pneumonia 

Septic pneumonia is relatively common in swine. It 
has occurred enzootically in swine affected primarily 



92 SWINE DISEASES 

with forage poisoning associated with pharyngeal paraly- 
sis. Sometimes it is a sequel to croupous pneumonia. 

Etiology. — The usual cause of septic pneumonia is 
the introduction of foreign substances into the lung. In 
cases of pharyngeal paralysis food escapes into the air 
tube. Drenching is another means by which foreign 
substances are frequently introduced into the lung. 
Thrombic obstruction of vessels supplying an area 
affected with croupous pneumonia favors the action of 
saprophytic bacteria, and hence putrefaction and the 
production of septic pneumonia. Abscesses sometimes 
become infected with putrefying organisms and produce 
septic pneumonia. The Bacillus necrophorous is active 
in the production of necrosis and putrefaction in the lung. 

Lesions. — Necrotic centers are most frequently found 
in the dependent and anterior part of the lung. The 
foci vary in size from that of a pea to a baseball, and 
may be few or many. They appear dirty brown, red, 
or dirty white in color. When incised they are found to 
be soft, the content being semifluid in the early stages 
but later of a cheesy consistency. The surrounding 
lung tissue will be inflamed. In the beginning, an 
infiltration circumscribes the lesions, but in the older 
lesions there may be a distinct capsule. Superficial 
necrotic foci may be associated with pleurisy. 

Symptoms. — The first symptom evidencing septic 
pneumonia is the foul -smelling exhaled air. This symptom 
does not occur in all cases, as the escape of putrid odors is 
dependent upon the erosion and discharge into the bron- 
chial tubes of necrotic putrid material. Rise of tempera- 
ture accompanies practically all cases of septic pneumonia. 
The fever may be irregular and intermittent, the thermal 
disturbance depending upon absorption of septic products. 
In those cases of (Croupous pneumonia in which septic 
pneumonia is a sequel, the general symptoms w^ill be the 
same, plus the offensive breath, as those observed in a 
case of croupous pneumonia A microscopic examination 
of the nasal discharge will reveal the presence of shreds 
of disintegrated lung tissue in cases of septic pneumonia. 



THE RESPIRATORY SYSTEM 93 

which fact is of diagnostic value. The course of septic 
pneumonia is uncertain. The attack may terminate 
fatally in two or three days after the onset of the disease 
or, if the septic lesions are limited in extent, they may 
become encapsulated and the animal recover, the length 
of time required varying from a few weeks to as many 
months. 

Treatment. — Remedial agents are of little, or no 
value so far as the septic process is concerned. The 
treatment of symptoms as they develop will be of some 
value. The animal should be given good care and 
sanitary surroundings provided. 

Interstitial or Chronic Pneumonia 

Interstitial pneumonia is a chronic condition char- 
acterized by proliferation of fibrous tissues. This con- 
dition is usually a sequel to chronic catarrhal bronchitis 
and chronic bronchopneumonia. It is observed in swine 
in those sections of the country where it is continuously 
dusty and in swine kept in quarters where slightly irri- 
tating gases prevail. 

Etiology. — Constant inhalation of mild irritants, such 
as dust or chemical fumes. 

Lesions. — Fibrous proliferation characterizes this 
disease. The fibrous tissue forms around the bronchioles, 
the process gradually extending and involving the alveoli. 
The bronchioles and alveoli also show evidence of catarrh. 
The affected lung is dense, and when cut offers more 
resistance than the normal lung. The degree of fibrous 
proliferation is quite variable in some instances; there is 
a limited amount, and in other cases the normal lung 
tissue is displaced by fibrous tissue. Encapsulated 
suppurative or necrotic centers may be found. 

Symptoms. — A persistent cough, associated with a 
limited but variable nasal discharge of a mucopurulent 
material, characterizes chronic pneumonia. The animals 
are usually unthrifty and emaciated. 

Treatment. — The cause should be removed and the 
animals properly housed and fed. Other than this, little 
can be done. 



94 SWINE DISEASES 

Tumors 

Various tumors have been encountered in the lungs 
of swine, but principally in autopsies or at abattoirs. 
Lung tumors of swine are similar to the same type of 
tumors of other tissues. Pulmonary neoplasms produce 
no typical symptoms by which they may be recognized 
clinically. 

Parasites 

The principal pulmonary parasite is the Metastrongy- 
lus Apri, which has been described under bronchial 
disorders. 

Echinococcosis pulmonum is a common disease of 
swine. This condition is caused by the larval form of 
Taenia echinococcus. The cysts of pulmonary echinococ- 
cus are the same as those occurring in the liver. 

Distomiasis, or invasion of the lung with flukes or 
Distoma, occurs but is not common in swine. 

Pulmonary stephanurosis has also been observed, but 
is rare. 

Parasitic nodules, the supposed result of invasion of 
some unknown parasite, are occasionally noted by 
veterinary inspectors, but there is little significance in 
such invasion as the lung is not edible, according to the 
meat-inspection regulations in the United States. 

PLEURA 

Disease conditions of the pleura of swine are rarely 
recognized clinically, though some cases of pleuro- 
pneumonia may be determined by a clinical examination. 
Pathologic conditions of the pleura are occasionally 
observed by veterinary inspectors in the carcasses of 
swine that are slaughtered. 

Hydrothorax 

Hydrothorax is a condition resulting from the accumu- 
lation in the thoracic cavity of excessive quantities of 
serous fluid. It is of rather rare occurrence in swine. 



THE RESPIRATORY SYSTEM 95 

Etiology. — ^Obstructed outflow of blood from the 
vena cava, with engorgement, is the principal cause of 
hydro thorax. Chronic disease of the cardiac valves and 
chronic pneumonia are the most common causes of 
obstruction of the outflow of venous blood from the 
vena cava. Tumors, abscesses, and malformed thorax 
may also be responsible for the causation of pneumo- 
thorax. 

Lesions. — Accumulation of varying quantities of a 
pale yellow fluid in the thorax is the characteristic lesion, 
and in addition the primary lesions in the heart or lung 
are usually evident. The accumulated fluid will com- 
press the lung. 

Symptoms. — It is not possible in the beginning to 
detect any particular symptoms. Those produced by 
the accumulated fluid are frequently so overshadowed 
by the primary condition that it is not possible to clini- 
cally diagnose hydrothorax until the advanced stages. 
There will be difficult respiration, and if the thoracic 
wall is not too thick a splashing sound may be noted 
synchronous with the heartbeat. An exploratory punc- 
ture with a small hypodermic needle will usually result in 
the discharge of serous fluid. 

Treatment. — ^Temporary relief may be obtained by 
withdrawing the fluid from the cavity, but permanent 
results cannot be expected until the primary causative 
factor has been removed or overcome. 

Hemothorax 

Hemothorax is a condition of the escape and accumu- 
lation of blood in the thoracic cavity. It is not a recog- 
nized clinical entity, particularly in relation to swine, 
yet it does occur, and is sometimes observed by inspectors 
of meat-food products. 

Etiology. — This condition is observed in swine that 
have been transported to market, and the affected swine 
at the time of autopsy show evidence of having been 
injured, probably while in transit. The injury may be 
a puncture, wound, or a contusion. 



96 SWINE DISEASES 

Lesions. — ^Accumulation of blood in the thorax 
characterizes thi§ condition. The blood may be coagu- 
lated, but it usually remains in the fluid state until the 
thorax is opened. The quantity of blood will depend 
upon the nature of the injury and the length of time 
elapsing after its infliction. If the hemorrhage is of 
long standing, pigmentation of the pleura may be the 
only evidence remaining. 

Symptoms. — The majority of animals affected with 
hemothorax show no symptoms. There may be paleness 
of the visible mucous membranes, weakness of the animal, 
and diflacult breathing due to compression of the lung, 
but these symptoms are evident only in those cases 
in which the hemorrhage is extensive. 

Treatment. — Medicinal treatment is of no value. 
Pneumothorax 

This is characterized by the accumulation of air in the 
thoracic cavity, a condition extremely rare in swine. 
The usual cause of the condition is injury in which the 
lung tissue is lacerated. The injury most frequently 
consists of fracture of a rib occasioned by improper hand- 
ling in transportation. 

The principal lesion observed consists of the primary 
injury. The thorax is found to contain air, and the lung 
is compressed. 

Pleurisy 

Pleurisy is inflammation of the pleura and may be 
serous, fibrinous, hemorrhagic, or purulent; acute or 
chronic. It is not a common condition among swine, at 
least in so far as. the clinical recognition of it is concerned. 

Acute Pleurisy 

Etiology. — Acute pleurisy is practically always the 
result of infection, although there are many predisposing 
factors that are active in diminishing resistance and thus 
increasing the possibility of successful infection. The 



THE RESPIRATORY SYSTEM 97 

causative organisms may gain entrance to the pleura 
from the lungs through puncture wounds, through the 
blood, and through the lymph. 

Lesions.— The pleura becomes hyperemic, tumefied, 
and dry. This stage is succeeded by an outpouring of a 
serous, fibrinous, or hemorrhagic exudate upon the 
pleural surface. Should the disease be due to the activity 
of pyogenic organisms the exudate will soon become 
purulent, and the future changes depend upon the nature 
of the exudate. Serous exudate may accumulate in 
quantities in the pleural cavity, and remain fluid 
although it may contain flakes of coagula. The 
fibrinous and hemorrhagic exudates coagulate early and 
produce greater or less adhesion of the visceral and 
parietal pleura. The hemorrhagic exudate is characterized 
by the presence of quantities of hemoglobin, which 
gives to it a red or blood color. 

Chronic Pleurisy 

Chronic pleurisy is characterized by the formation of 
varying quantities of fibrous tissue which produce per- 
manent adhesions of the two layers of the pleura. There 
may also be considerable quantities of a fluid (serous) 
exudate in the pleural cavity, and there may be abscess 
formation, the pus being circumscribed by a definite 
capsule. 

Symptoms —Difficult breathing, each effort being 
accompanied by a grunt, and sensitiveness of the thorax, 
characterize pleurisy. In the acute cases there is inap- 
petence, high temperature, and usually constipation. 
Chronic cases frequently show little evidence of dis- 
turbance. 

The acute type has a relatively short course, ter- 
minating in recovery, or in death within a few days. 
The chronic form may persist for weeks or even months. 

Treatment. — Remove the cause of the trouble and 
estabhsh sanitary conditions. The treatment of symptoms 
as they arise will be of some value. If an excessive 



98 SWINE DISEASES j 

quantity of serous fluid accumulates in the pleural cavity ■ 

it should be withdrawn. a 

Tumors 

Pleuritic tumors are not common in swine. Fibromas i 

have been encountered on a few occasions. Of the j 

malignant tumors, endothelioma and sarcoma pre- | 

dominate, but are unusual. ] 

l 



SECTION III 
THE URO-GENITAL SYSTEM 

SWINE are prone to various disease conditions of 
the organs constituting the uro-genital system. 
This may be due to the nature of their food stuff, 
which is often fermented or putrid. 

KIDNEYS 

Kidney diseases are especially common in swine. 
Frequently the pathologic condition of the kidney is not 
of sufficient intensity to produce recognizable symptoms, 
but a diseased condition is easily detected by autopsy or 
on inspection of the carcasses of dressed hogs. 

Malformations 

There may be a total absence of one or the other 
kidney. A horseshoe-shaped kidney is also occasionally 
observed. Floating kidney has been reported, but from 
the number of recorded cases the condition is relatively 
rare. 

Hydronephrosis 

Hydronephrosis, or cystic kidney, is of frequent 
'occurrence in swine. It is very commonly encountered 
by the food inspector. Tucks reported 0.67 per cent of 
cystic kidneys in over six thousand hogs examined, and 
the writer found this condition in the kidneys of twenty- 
nine swine in three thousand examined. The condition 
may affect one or both kidneys. 

Etiology. — Obstructed outflow of urine is the primary 
cause of cyst formation in the kidney. The anatomical 
arrangement of the openings of the ureters into the 
bladder predisposes to their obstruction and therefore to 
the accumulation of urine in the kidney pelvis. Renal 
and pelvic calculi and inflammatory products occasion 



100 SWINE DISEASES 

obstruction of collecting tubules and favor cyst formation. 
Cicatrization of newly formed fibrous tissue may obstruct 
the outflow of urine and cause cyst formation. Complete 
obstruction of the ureters or kidney pelvis will not as a 
rule result in hydronephrosis, as this condition results in 
a compensatory activity on the part of the normal 
kidney. 

Lesions. — Hydronephrosis may occur as cysts in the 
renal substance^ or the kidney may be practically replaced 
by a variable-sized watery bag. The cysts vary in size 
from a pinhead to an inch in diameter. There may be 
myriads of the small cysts scattered throughout the 
kidney but occurring primarily in the cortical portion. 
The larger cysts are usually not numerous and they 
frequently represent the fusion of small cysts. The cysts 
have a bluish-white color, are definitely surrounded by a 
distinct capsule, and the content is thin and watery. 
The kidney substance between the cysts is atrophied, 
due to pressure. In extreme cases the kidney capsule 
may serve as the cystic capsule, the entire mass being 
much enlarged and the small atrophied kidney floating 
within. Richter reported a case of a hydronephrotic 
kidney weighing over ninety pounds. 

Hemorrhage 

Kidney hemorrhage is relatively common in swine, 
not as a primary condition, but associated with some 
disease. The extravasated blood may escape into the 
uriniferous or collecting tubules, producing hematuria, 
or it may escape into the kidney tissue. 

Etiology. — Injury of the capillaries, either glomerular 
or tubular, may result in hemorrhage. The vessels are 
most frequently damaged by chemical substances that 
are being eliminated in the urine or by products of 
bacteria produced in the kidney or elsewhere in the 
body. 

Lesions. — Escaped blood into the uriniferous tubule;^ 
may be detected by examination of the urine, which, by 
the way, is very infrequently done. The urine will be 



THE URO-GENITAL SYSTEM 101 

discolored with hemaglobin and will contain blood casts. 
Renal-tissue hemorrhages may be extensive or Hmited, 
but rarely is extensive extravasation observed in the 
kidney. Small-tissue hemorrhages, particularly petechial 
hemorrhages, are of common occurrence in the kidney of 
swine affected with hog cholera. Such hemorrhages 
have been observed in the kidney of otherwise apparently 
healthy swine in which no other lesions of cholera could 
be detected, and the blood from these hogs, when injected 
into healthy, susceptible pigs, failed to produce evidence 
of hog cholera. These hemorrhages were not numerous; 
sometimes only a very few could be recognized by a 
careful examination; their exact relation has not been 
discovered. The petechial hemorrhage of cholera merely 
evidences a vascular disturbance. 

Symptoms. — Hematuria indicates hemorrhage into 
the urine in the kidney, ureter, bladder, or urethra. Renal 
hematuria is characterized by bloody urine and the 
presence of, blood- tube casts. 

Fatty Changes 

The occurrence of the so-called large white kidney is 
a common experience, at least to those engaged in meat 
inspection. *'Large white kidney" is a name apphed to 
two different conditions— fatty kidney and fibrous kidney. 
The fatty white kidney is less common than the fibrous 
white kidney. 

Etiology. — Some renal vascular disturbance resulting 
in blood disturbance in the kidney or general malnutrition 
appears to be the causative factor in the production of 
fatty kidneys. 

Lesions. — The affected kidney is large and creamy 
white in color. The capsule is easily stripped, and the 
kidney substance is soft and feels greasy. Only one 
kidney is affected in those cases in which the kidney is 
exceedingly large. Both kidneys may be affected, but 
to a limited degree. 

Symptoms. — No primary symptoms characterize 
this condition. It is detected only in autopsy. 



102 SWINE DISEASES 

Calculi 

Renal calculi occur but are not common in swine. 
They may occur in the collecting tubules but are more 
likely to be found in the renal pelvis. 

Etiology. — The formation of renal calculi is usually 
associated with an obstructed outflow of urine. Retained 
urine in the renal pelvis or in the collecting tubules has a 
tendency to undergo fermentation, with the production 
of an unbalanced condition of the chemical constituents 
resulting in precipitation. Retained urine and fermenta- 
tion also favors catarrhal inflammation. The muco- 
purulent discharge may serve as a nucleus upon which 
the precipitate is deposited. 

Lesions.— Retention of urine and catarrhal inflam- 
mation are usually evident. The calcular deposits may 
be very small and difficult to detect or they may be 
quite large, one having been observed that practically 
filled the renal pelvis. The calculi may be variable in 
shape, color, and consistency, depending upon their 
composition, and are composed of magnesium or calcium 
phosphates, urates, or carbonates. 

Symptoms. — Cloudy urine, particularly when the 
last discharge contains quantities of brownish deposit, 
will be observed if the calculi are passing out. The 
animals will have colicky pains, the loins will be sensitive, 
and the animals will stand with arched back. If the 
calculi are small and remain in the kidney there may be 
no evident symptoms. 

Treatment. — ^If the patient is in good condition it 
will be most economical to sell it for slaughter. Very 
little can be done toward the actual solution of the 
formed calculi. 

Congestion 

Congestion of the kidneys is common in swine fed on 
putrid or fermented foods. It may occur as a result of 
undue exposure, to cold experienced in shipping, or it 
may be due to injury. The condition is associated with 
erysipelas, hog cholera, and some forms of pneumonia. 



THE URO-GENITAL SYSTEM 103 

Etiology. — Chemical poison obtained in food, by- 
products of infection, or destructive metabolism cause 
renal congestion. Exposure and injury may also produce 
this condition. 

Symptoms. — Stiffness and a stilty gait due to 
hypersensitiveness of the loins usually accompany con- 
gestion. There is also frequent urination in which an 
excessive quantity of urine is voided. 

Treatment. — Remove the cause, give good food, 
and provide sanitary surroundings. Alkaline diuretics 
may be of value, and laxatives may also be used to 
advantage. 

Nephritis 

It is not possible with the present available knowledge 
to classify the inflammatory disturbances of the kidney 
in a satisfactory manner. The principal knowledge of 
porcine nephritis has been obtained from investigation 
by veterinarians in food-inspection service. The con- 
dition is rarely recognized clinically, or at least the 
reports of clinical cases of nephritis in swine are very 
rare. Urinalysis is not practiced systematically by 
veterinarians, and the analysis of swine urine by prac- 
titioners is practically an unheard-of procedure. Accord- 
ing to the findings of the veterinary inspectors, porcine 
nephritis is very common. In some instances nephritis 
appears to be the only pathologic condition existing, but 
it is also an accompanying pathologic factor in such 
diseases as hog cholera, swine plague, septicemia, and 
pneumonia. 

Acute Parenchymatous Nephritis 

This is an inflammation of the cells of the glomeruli 
and convoluted tubules and is characterized by a rather 
rapid onset, tumefaction, and frequently destruction of 
the affected epithelium. 

Etiology. — Exposure to cold and injuries of various 
kinds predispose to this disease. The specific exciting 
causes are usually chemical substances that are being 
eliminated through the renal epithelium. Bacterial 



104 SWINE DISEASES 

products, and vegetable and mineral poisons, when 
present in sufficient quantities, are capable of establishing 
inflammation. Thus pneumonia, hog cholera, swine 
plague, and septic infections are usually accompanied by 
nephritis. Some serum producers have had Tosses of 
hyperimmune swine due to contaminated virus. In the 
swine that died in these cases not only the lesions evi- 
dencing general septic infection were present but also 
marked lesions of an acute parenchymatous nephritis. 
Turpentine, phenol, and the various coal-tar products are 
capable of producing nephritis. Corrosive sublimate, 
too, may be obtained in sufficient quantities to produce 
the disease. 

Lesions. — The lesions of acute parenchymatous 
nephritis are practically confined to the epithelium of the 
glomeruli and convoluted uriniferous tubules. The 
affected kidney is slightly enlarged and has a parboiled 
appearance. The capsule is easily removed, the kidney 
substance is usually soft, and blood escapes freely from a 
cut surface. Microscopically the affected epithelium is 
affected with hyperemia and cloudy swelling which may 
become so intensive that the cells undergo necrosis. The 
detritis of the dead cells and coagulated exudate, accumu- 
lated in the lumina of the tubules, may be readily ob- 
served. The intertubular tissue may be infiltrated with 
leukocytes. If the inflammation is intense there may be 
hemorrhage into the kidney Substance or into the glom- 
eruli or tubules. 

Symptoms. — ^The animals show evidence of dis- 
tress. One of the first indications of the disease is arched 
back and stilty gait. There are frequent attempts at 
urination, but little urine is voided, and the animals usually 
have a temperature ranging from 104 to 106 degrees 
Fahrenlieit. In the beginning of the attack they may 
eat, but inappetence becomes evident soon after the 
onset. It is possible that the foregoing symptoms are not 
characteristic of uncomplicated nephritis, but of cases in 
which nephritis was the most prominent condition. In 
the cases that have been observed the disease most 



THE URO-GENITAL SYSTEM 105 

frequently terminated fatally in from two to four days 
after the onset, the few cases that recovered requiring 
from one to six weeks. 

Treatment.— The treatment of nephritis in swine is 
a difficult problem. Resort should be had to the usual 
hygienic practices. Diaphoresis is not practical in swine, 
and purgation should not be resorted to as a means of 
elimination, for such procedure would probably aggravate 
the condition existing in the kidney. General treatment 
of symptoms as they arise is probably all that can be 
accomplished therapeutically until further knowledge is 
obtained. 

Acute Interstitial Nephritis 

An occasional kidney is found in which there is a 
leukocytic invasion and other evidence of a reaction in 
the interstitial or supporting tissue, the parenchymatous 
tissue being unaffected. But this condition is not com- 
mon, and thus far has not been observed clinically in 
swine. 

Purulent Nephritis 

Purulent nephritis is inflammation of the kidney 
characterized by the formation of pus, a condition of 
frequent occurrence in swine. In the study of swine 
kidneys from abattoirs one-half of one per cent have 
been found affected. 

Etiology.— Pyogenic cocci and the colon bacteria are 
the most common causative agents. Purulent inflam- 
mation elsewhere in the body predisposes to renal meta- 
stasis, although purulent inflammation may occur pri- 
marily in the kidney Constipation is probably a pre- 
disposing factor of colon-bacillus invasion of the kidney. 

Lesions.— Suppuration may be circumscribed, thus 
torming an abscess or multiple abscesses, or it may be 
diffuse. Metastatic purulent nephritis usually involves 
both kidneys, and small suppurative centers occur as 
gray or yellow areas which are surrounded by a hvperemic 
zone. The larger foci may be quite definitel/ circum- 
scribed and frequently have small bands of fibrous 



106 SWINE DISEASES 

tissue extending from the capsule into the purulent 
center. Microscopically the small centers are found in 
the beginning to be collections of leukocytes and later of 
pus. The surrounding parenchymatous tissue will be 
affected with cloudy swelling, as in acute parenchymatous 
nephritis. 

Symptoms.— Practically the same symptoms are 
observed in purulent nephritis as in acute parenchymatous 
nephritis, except that in those cases in which there is 
absorption of quantities of pus, when there is evidence 
of pyemia. 

Treatment. — Symptomatic treatment may be of 
value. The cause should be removed, and the patient 
given sparingly of easily digested food. 

Chronic Nephritis 

Chronic nephritis is a common condition in swine. 
It is not an important disease from the viewpoint of the 
practitioner, but it is of some economic importance to 
the packer as many kidneys are found to be affected. 
Chronic nephritis represents a group of pathologic con- 
ditions — at least, there is a variety of different types of 
lesions observed. One type of chronic nephritis has been 
studied and named "chronic non-indurative nephritis," 
but from the general lesions in these kidneys it seems 
probable that the condition is confined to the parenchyma 
and should be called "chronic parenchymatous neph- 
ritis." 

Chronic Interstitial Nephritis 

Typical chronic interstitial nephritis is characterized 
by the proliferation of fibrous tissue which may or may 
not cicatrize. This condition includes white-spotted 
kidneys, some large white kidnej^s, granular kidneys, 
sclerotic atrophied kidneys, and all variations of the 
foregoing. 

Etiology. — Chronic nephritis, especially the type 
involving only the supporting framework, is caused 
primarily by relatively mild irritants acting over a long 
period of time. These cases have not been recognized 



THE URO-GENITAL SYSTEM 107 

clinically, but by tracing the swine that show the lesions 
when slaughtered it is usually found that the feed of the 
animals has been at fault. In some cases parasites and 
calculi are responsible for the condition. 

Lesions. — Chronic parenchymatous nephritic kidneys 
are enlarged. The capsule is not easily removed, and 
when pealed off small fragments of kidney tissue remain 
attached to it . The kidney is mottled, due to hemorrhages 
and infarction, and there is no definite line of demarca- 
tion between the medulla and cortex. Microscopically 
the parenchymatous cells are found enlarged and cloudy, 
but tube casts are rarely observed. 

Chronic interstitial nephritis is characterized by 
fibrous proliferation. The newly formed fibrous tissue 
may or may not cicatrize. The gross appearance of the 
kidney varies according to the amount and disposition of 
fibrous tissue. If the condition is locahzed according 
to the distribution of small arteries the fibrous tissue will 
occur in foci, and spotted kidney is the result, the white 
spots being masses of fibrous tissue. If this fibrous 
tissue is uniformly deposited throughout the kidney and 
does not cicatrize, the kidney is enlarged, dense, and 
hard— one of the types of the large white kidney. Granular 
kidneys are the result of the proliferation, and later 
cicatrization, of fibrous tissue in and around the glomeruh 
or tubules. Granular kidneys have rough, small pro- 
jections thickly studded over the surface; such kidneys 
are usually of a red color. The extensive proliferation 
and cicatrization of fibrous tissue in all the cortical 
substance, when associated with a thickening of the 
capsule, produces the small, hard, or sclerotic kidney. 
Microscopically excessive quantities of fibrous tissue are 
found, and the parenchymatous tissue is diminished, due 
to pressure atrophy. Sometimes there may be large 
areas of fibrous tissue in which no parenchymatous tissue 
appears or only remnants of tubules or glomeruli. 

Symptoms.— Records of the clinical evidence of 
chronic interstitial nephritis in swine are wanting. Swine 



108 SWINE DISEASES 

with extensive kidney lesions are usually in fair condition 
when they are observed at the time of slaughter. 

Treatment. — ^The application of therapeutic agents 
for the relief of chronic interstitial nephritis in swine has 
not been practiced. Should such a case be diagnosed, 
the removal of the cause and the provision of good 
quarters and wholesome food would probably be suf- 
ficient until the animal was in condition for slaughter. 

Pyelonephritis 

Pyelonephritis is an inflammation of the pelvis of the 
kidney, a condition that has been observed in swine but 
is rare. 

Etiology. — Calculi and parasites are frequently pre- 
disposing factors in this disease. Primarily, the disease 
is the result of infection. Pyogenic bacteria may cause 
the condition, but more frequently it is caused by a 
pleomorphic organism that has been named corynehacillus 
renalis. 

Lesions. — The pelvis of the kidney is dilated with a 
thick, brownish, purulent fluid and tissue shreds. The 
mucosa of the renal pelvis is thick and contains hemor- 
rhagic spots. The kidney may contain purulent centers 
or it may be converted into a purulent mass. 

Symptoms. — Frequent urination is a symptom of 
this disease, the urine voided being cloudy. Loin sensi- 
tiveness and inappetence are also observed in these 
cases. 

Treatment. — Thus far no treatment has been found 
that is of any value. 

Albuminuria 

Albuminuria is a condition in which there is elimination 
of albumin in the urine. 

Urinalysis is now in its infancy in veterinary medicine. 
Considerable time and energy have been devoted to the 
study of urine from some animals, particularly the horse, 
but little attention has been given to systematic urinalysis 
of swine. 



THE UROGENITAL SYSTEM 109 

Urine lias been collected from the bladder of the 
carcasses of swine that have been slaughtered, and 
analyzed. It is possible that there may be some modi- 
fication of the urine of slaughtered animals, but it is 
doubtful if the changes are of much significance. 

Albuminuria has been found to exist in swine showing 
a high temperature, particularly cases that have been 
affected with cholera. The urine has also been found to 
contain varying quantities of albumin in which there was 
an acute nephritis. Pneumonic cases also evidenced 
albumin in the urine. 

The exact cause of albuminuria is still being debated. 
The condition in swine, as well as in other animals, 
occurs in those cases where the renal epithelium is dam- 
aged either by degeneration or inflammation, although it 
may occur in the absence of damaged epithelium. Some 
veterinarians are maintaining that albuminuria is caused 
by acid intoxication. 

At this time, with our present knowledge, albuminuria, 
at least in swine, must be thought of as secondary to some 
other conditions. Albuminuria in swine has not been 
studied clinically, therefore, symptoms of the condition 
cannot be recorded. It is an important condition 
because albuminous substances that should be conserved 
are eliminated from the body in the urine. Disturbances 
of nutrition follow, and the primary and associated con- 
ditions produce emaciation and marasmus. Albuminuria 
usually terminates fatally. 

Uremia 

Uremia is a condition characterized by the presence 
in the blood of a greater or less amount of the solid 
constituents of urine. This condition has not been 
identified clinically in swine, but the nature of the lesions 
observed in some kidneys by veterinary inspectors is 
sufficient evidence that the disease exists in swine. 

Etiology. — The primary cause of uremia is obstructed 
outflow of urine, which may be the result of disturbance 
in the kidneys, ureter bladder, or urethra. Severing or 



110 SWINE DISEASES 

puncturing the ureters during operations, as in cesarean 
section, may result in uremia. 

Lesions. — ^No particular gross tissue changes are 
attributed to uremia. The lesions found are those 
incidental to the obstruction of the outflow of urine, as 
calculi, tumors, and so on. 

Symptoms. — Stupor, vertigo, emesis, inappetence, 
diarrhea, clonic muscular spasms, and convulsions are 
the principal symptoms of uremia. The disease, at 
least in the acute form, is usually fatal. Chronic uremia 
is associated with digestive derangements. 

Treatment. — Removal of the cause is practically 
always successful unless the case is too far advanced. 
Therapeutic treatment is of no value. 

Parasites 

The cystic form of the Taenia solium of man has been 
observed in the kidney of swine, but is not of common 
occurrence in that location. The cystic forms of the 
tsenic echinococcus also occur in this organ. 

The Stephanurus dentatum is sometimes found in 
the kidney structure, although it more commonly occurs 
in the perirenal fat. 

Tumors 

The kidney of swine is affected with adenosarcoma. 
In the living swine the presence of these tumors is not 
suspected. They appear as irregular, incapsulated 
masses, usually involving only one kidney, and in size 
vary from five to fifteen pounds. Although they have 
not been recognized clinically, their structure and appear- 
ance evidence rapid growth. They have their origin in 
the kidney substance near the pelvis, and the tumor 
tissue produces pressure atrophy of the renal parenchyma. 
The outline of the tumor is irregular and frequently 
lobulated. On being sectioned, fibrous bands are found 
extending in various directions and dividing the tumor 
mass into lobes. The neoplastic tissue is of a white or 
dirty-white color, but is often mottled, due to hemor- 



THE URO-GENITAL SYSTEM 



111 



rhage; there may also be grayish-yellow centers of necrosis. 
Microscopically these tumors are composed of embryonic 
epithelium and connective tissue, the epithelium disposed 
as irregular tubules or remnants of tubules, while the 
connective tissue occurs around and between the epi- 
thelia tumor cells. Sometimes larger areas of embryonic 




Tig. 4.— ADENO- SARCOMA OF THE KIDNEY. 

A. Normal kidney tissue. B. hcmorrhag'ic areas. C. pelvis. D. sar- 
comatus tissue. (This kidney was seven or eiglit times as large as 
a normal kidney.) 

connective tissue cells are found independent of epi- 
thelium, and again the epithelium may occur in nests in 
the sarcomatous tissue. 

The time for growth of these tumors has not been 
determined, but they are most frequently found in swine 
less than two years of age. 



112 SWINE DISEASES 

Sarcomas have also been encountered by veterinary 
inspectors in the kidney of swine. They are usually 
metastatic, although one case of a primary, large-spindle 
celled sarcoma has been recorded. 

URETERS 

Malformations 

Malformations of the ureters are not uncommon, but 
the malformations that are observed are not of such a 
nature that the function of the organs is interfered with 
and therefore are of no practical importance. 

Renal pelvic calculi may become lodged in the ureters 
and establish inflammatory^ disturbances, and also obstruct 
the lumen. 

The ureters are subject to injuries in spaying and other 
abdominal operations. 

BLADDER 

Malformations 

Malformations of the bladder are not common. A 
few cases of double bladder have been recorded, or the 
bladder may be very small, such animals urinating 
frequently. Vestiges of the urachus may be retained, 
and these may become cystic. 

Hematuria 

Hemorrhages into the bladder sometimes occur in 
swine. They are caused by injuries which may be 
inflicted by calculi and from diseases of the mucosa. 
They may also be caused by drugs, such as cantharides 
and turpentine, obtained accidentally in large quantities. 
This condition is frequently associated with such diseases 
as hog cholera. 

Lesions. — The primary lesions observed depend 
upon the cause of hematuria. There may be cystic 
calculi, injuries of various kinds, infection, and lesions 
elsewhere in the body. The extravasted blood will be 



THE URO-GENITAL SYSTEM 113 

accumulated in the bladder and may or may not be 
coagulated, and the entire bladder content will be colored 
red with hemaglobin liberated from the disintegrated red 
blood cells. 

Symptoms. — Hematuria is evidenced by bloody 
urine in which the entire urine is uniformly red. It is 
distinguished from renal hemorrhage by the absence of 
tube casts, and from urethral hemorrhages by the fact 
that in urethral hemorrhage only the first urine voided is 
red. 

Treatment. — The exact cause should be identified 
and removed. Urinary sedatives may also be of value. 

Dilatation 

Cystic dilatation is sometimes occasioned by urethral 
obstruction or spasms of the muscles in the neck of the 
bladder. The urine continues to be produced in the 
kidney and accumulates in the bladder until its capacity 
may be far in excess of the normal. 

Lesions. — The characteristic lesion of dilatation con- 
sists of distention of the bladder and attenuation of its 
walls. In fatal cases the bladder ruptures and urine and 
uriniferous odor are detected when the abdomen is opened, 
and the rent in the bladder wall will also be evident. 

Symptoms. — Distress, anuria, frequent attempts at 
urination, and possibly some enlargement of the abdomen 
characterize distended bladder. In distention succeeded 
by rupture the foregoing symptoms would be succeeded 
by stupor, vertigo, emesis, inappetence, diarrhea, clonic 
muscular spasms, convulsions, and death. 

Treatment. — Treatment is available only during 
distention, and effort should be directed principally to 
removing the cause. If it is a urethral obstruction in the 
male and the obstruction is below the ischiatic arch an 
artificial opening may be made into the urethra where it 
passes over the ischiatic arch, giving temporary relief, 
and if the obstruction cannot then be removed the tem- 
porary opening in the urethra may be made permanent. 
In valuable animals obstructive calculi may be removed 



114 SWINE DISEASES • 

from the bladder by surgical procedure and the condition 
thus corrected. Tumors and abscesses that affect 
urethral obstruction may be removed and permit of the 
ready outflow of urine through the urethra. 

Calculi 

Cystic calculi are of common occurrence in swine. 
There may be a single calculus or there may be myriads 
of them. In size they vary from mere grains of sand to 
masses as large as English walnuts. In shape they may 
be spherical, ovoid, or all kinds of irregular surfaces and 
outlines may be presented. Some have been observed 
that were practically the shape of jack straws. When 
several occur together they may be faceted. As a rule 
they are of a dirty-white color, though they may be of 
any color. They are usually composed of magnesium 
and calcium phosphates and carbonates. 

Etiology. — Retention and fermentation of urine in 
the bladder favor calculous formation. Retention and 
urine fermentation also favor catarrhal inflammation, 
which is associated with epithelial desquamation, and this 
serves as a nucleus for the calculous deposits. 

Lesions.— The presence of calculi is the principal 
thing to be sought for, and they are not difficult to 
identify. There is also more or less evidence of catarrhal 
cystitis, and there may be retention of urine. 

Symptoms. — Evidence of catarrhal cystitis — that is, 
frequent voiding of relatively small quantities of urine — 
characterizes most cases of cystic calculi. The urine in 
these cases is frequently acrid and may produce dis- 
turbances in and around the prepuce of the male and in 
the perineal region of the female. Should the calculi 
produce obstruction to the outflow of urine there will be 
symptoms of cystic distention. 

Treatment. — Solvents for cystic calculi are not 
wholly successful. If the calculi are causing such dis- 
turbance that marked symptoms are evident, operative 
procedure is indicated, providing the value of the animal 
is sufficient to justify it. 



THE URO-GENITAL SYSTEM 115 

Cystitis 

Inflammation of the bladder may be catarrhal or 
purulent. Neither type has been extensively investi- 
gated by the clinician, therefore the present knowledge 
concerning them has been obtained by veterinarians at 
abattoirs. 

Catarrhal Cystitis 

Catarrhal cystitis is not uncommon. In many 
instances the condition is associated with cystic calculi, 
but it may also be caused by infection. Occasionally 
several cases of catarrhal cystitis may occur simultaneously 
or successively in the same herd, and on obtaining the 
history it is found that the affected swine have been fed 
food stuff containing some urinary irritant or they have 
obtained quantities of turpentine or can thar ides. Reten- 
tion and fermentation of the urine predisposes to inflam- 
mation of the cystic mucosa because of the liberation of 
ammonia. 

Lesions. — Catarrhal cystitis is characterized by the 
following sequential lesions of the mucosa: hyperemia, 
tumefaction, and coating of the surface with tenacious 
mucus, desquamated epithelia, and pus cells. Later 
there is desquamation of the surface epithelium, leaving 
a denuded granulating surface. 

Symptoms. — Frequent attempts at urination in 
which small quantities of a turbid urine is eliminated 
are symptoms of catarrhal cystitis. There may be a 
straddling gait. 

Treatment. — Remove the cause. The bladder in 
females may be cleansed by a weak solution of corrosive 
sublimate or creolin, and urinary sedatives should be 
administered. Internal treatment is practically all that 
can be given in male animals affected with cystitis. 

Purulent Cystitis 

Purulent cystitis is an inflammation of the urinary 
bladder accompanied by the formation of pus; This 
condition is not so common in swine as catarrhal cystitis. 



116 SWINE DISEASES 

Predisposing causes mentioned in catarrhal cystitis are 
also operative in purulent cystitis. The exciting cause is 
most frequently the Bacillus coli communis, although 
any of the pyogenic cocci may produce it, or even the 
Bacillus pyocyaneus being responsible for an occasional 
case of cystitis. 

Lesions. — Hyperemia, tumefaction of the mucosa, 
accumulation of tenacious mucus upon the mucosa, and 
the production of pus in quantities characterize purulent 
cystitis. The surface mucosa is eroded and becomes a 
granulating surface. 

Symptoms. — Frequent urination and the voiding of 
small quantities of urine admixed with pus typifies 
purulent cystitis. 

Treatment. — Remove the cause, and cleanse the 
bladder of females with weak antiseptics. The males 
should be treated by internal medication, with urinary 
antiseptics and sedatives. 

Tumors 

Very few cases of the occurrence of tumors have been 
observed in the bladder of swine. Papillomata have 
been reported in a few cases. 

URETHRA 

The urethra may be imperforate, particularly in the 
male. Such cases are rarely observed, and those affected 
die soon after birth. The condition is easily remedied, 
providing the imperforation is near the outlet, by making 
a crucial incision or by puncture with a small trocar. 

Injury of the urethra in males may be inflicted by 
contact with barbed wire or other sharp objects, and the 
female urethra may be injured by forceps used during 
parturition. These injuries are not serious, though 
occasionally they may result in permanent fistulas. 

Stricture 

' [ Stricture of the urethra may follow injuries or inflam- 
mation. In male swine catheterization is not prac- 



THE URO-GENITAL SYSTEM 117 

ticable, and it is not an easy matter to locate a stricture 
or other obstruction in their urethrse. 

Urethritis 

Urethritis occurs in swine. It is most frequently a 
sequel of cystitis, although it may occur as a primary 
condition. It is probably more common in males than 
in females, and is evidenced by painful urination. Treat- 
ment consists in giving urinary sedatives and inducing 
the animals to drink large quantities of clean, wholesome 
water in order that the urine may be diluted. 

MALE GENERATIVE ORGANS 

PROSTATE GLAND 

The prostate gland is located beneath the vesiculai 
seminales and embraces the neck of the bladder. This 
gland is not well developed except in boars. It is occa- 
sionally enlarged, due to infection with tubercle bacilli, 
colon bacilli, or pyogenic cocci. There may be abscess 
formation or fibrous proliferation in the prostate. En- 
larged prostates partially obstruct the urethra by pressure, 
thus making urination difficult. 

BULBO-URETHRAL OR COWPER'S GLANDS 

These are large glandular structures located on either 
side of the posterior portion of the pelvic urethra. They 
are less developed in the castrated animal, particularly 
if the operation be done in early life. They are also 
subject to infection and enlargement which produces 
pressure obstruction upon the urethra. 

TESTICLES 

Malformations of the male sexual glands are not 
uncommon, one or both testicles sometimes being abnor- 
mally small. Cryptorchidy is of common occurrence in 
swine. De Wolf inspected 4,671 male swine and found 
twenty-eight single and seven double cryptorchids. 
Nearly five per cent of the male progeny of one of Mis- 



118 SWINE DISEASES 

souri's most famous boars, Chief Tecumseh II, were 
cryptorchids. Liberty Chief and Chief I Know, two 
boars sired by Chief Tecumseh II, were noted breeders, 
and from three to five per cent of their get were cryp- 
torchids. Chief Perfection II, sired by Chief Tecumseh 
II, was the sire of Chief Cherokee Perfection, that in 
turn sired about three per cent of cryptorchids. Cryp- 
torchidism diminishes the value of a pig because of the 
greater castration risk. 

Because of their location, the testicles of a boar are 
subject to injuries of various kinds. Some instances 
have been observed in which it was necessary to castrate 
valuable boars that had their testicles so lacerated that 
recovery of the function of them was not possible. In- 
juries may be inflicted by dogs, sharp-cutting objects, or 
by crushing, as a result of cattle or horses treading upon 
the glands. 

Orchitis and Epididymitis 

Inflammation of the testicle has been observed, but 
is not of common occurrence in swine. Orchitis and 
epididymitis are not easily differentiated. They are most 
frequently the result of mechanical injury, although 
they may result from infection. Tuberculous orchitis is 
not uncommon in swine. 

Lesions. — The affected testicles or epididymi are en- 
larged and hyperemic. The secreting structure have a 
parboiled appearance. Suppurative orchitis is charac- 
terized by the formation of abscesses, or it may assume a 
diffuse form of suppuration in which pus infiltrates the 
tubular and intertubular tissue. 

Microscopically, the arterioles and capillaries are 
gorged with blood, and there is exudation into the 
seminiferous tubules and intertubular spaces of leukocytes 
and plasma. The spermatogenic cells are cloudy and 
may show disintegration. The spermatozoa are more or 
less disintegrated and inactive. 

Symptoms. — Enlarged, sensitive testicles are the 
chief symptoms by means of which orchitis or epididy- 



THE UROGENITAL SYSTEM 119 

mitis is identified. There may be abnormal sexual 
excitement. 

Treatment. — Unless the animal is very valuable for 
breeding purposes, castration should be resorted to; 
otherwise, remove the cause and apply hot compresses, 
or alternating hot and cold compresses, upon the affected 
glands. Place the patient in comfortable quarters and 
where there will be no occasion for sexual excitement. 

Tumors 

Testicular tumors are not common but appear as 
frequently in swine as in other animals. Both dermoid 
and dentigerous cysts have been encountered in the 
testicle, and while these are not destructive to life, they 
damage the animal for breeding purposes. Sarcomas and 
endotheliomas occasionally occur in the testicle, and are 
usually primary. They are malignant tumors, however, 
and swine with enlarged testicles are usually castrated. 
Fortunately, the operation is commonly performed 
before the tumors have metastasized, and thus the lives 
of the swine are not sacrificed. 

SEQUELS TO CASTRATION 

Castration of male swine is the usual practice. The 
proper age that pigs should attain before being castrated 
depends somewhat upon climatic conditions. Castration 
as a rule should be done about weaning time, for if there 
should be any fatalities from the operation the loss will 
be less then than later. It should not be delayed until 
the swine are matured, or the meat will have a strong 
flavor. Some have made a practice of castrating imme- 
diately after the pigs are farrowed — usually with good 
success, as the operation does not appear to hinder 
development. 

Castration of swine is usually practiced by the lay- 
man and only occasionally do bad results ensue. 

Hemorrhage 

Rarely does a pig bleed to death as a sequel to cas- 
tration, but this does occur occasionally. Old boars are 
prone to bleed freely unless proper precaution is taken. 



120 SWINE DISEASES 

Infection 

The castration wounds are subject to a variety of 
infection because of their location and the nature and 
habit of swine. Various pyogenic bacteria gain entrance 
into the castration wound, and should the incisions be 
small and the wound margins closed by the inflamma- 
tory swelling an abscess may develop, the size of which 
will depend upon the tissue resistance. Scrotal abscesses 
in castration wounds are not serious if properly opened, 
drained, and cared for, but if the pus is allowed to accumu- 
late it may infiltrate the surrounding tissues or, more 
probably, pass along the vas deferens, and ultimately 
enter the pelvic cavity and establish peritonitis. 

The colon bacillus may also infect castration wounds 
and produce either suppurative or septic inflammation. 
In a few instances several pigs have been observed 
affected with septic disturbances resulting from colon 
infection in castration wounds. The lesions observed in 
septic infection consist of gaseous tumefactions containing 
inflammatory products. These cases usually terminate 
fatally, unless treatment is begun early. The treatment 
consists of opening the castration wounds, removing 
the necrotic tissue with a curette, and freely applying 
efficient germicidal agents. 

The Bacillus necrophorous occasionally gains entrance 
to the castration wounds, but the successful infection by 
these germs is usually in the later stages of the healing 
process. The Bacillus necrophorous is anaerobic and 
probably is continuously eliminated in the feces. The 
lesions produced by this organism consist of a slow-going 
necrosis, the necrotic foci being surrounded by an inflam- 
matory zone. A peculiar, offensive odor emanates from 
the lesions. The necrotic areas may later show evidence 
of separation from the surrounding tissue, and ultimately 
the lesion may become desiccated and slough, leaving a 
dark-colored surface upon which tissue fragments and 
pus may accumulate. These cases may prove fatal, 
but more frequently the animals linger for some time, 
the surrounding tissue becoming tumefied due to the 



THE URO-GENITAL SYSTEM 



121 



proliferation of fibrous tissue. In such cases there is a 
variable sized opening or unhealed surface. If the 
large fibrous mass is removed and incised it will be found 
to contain necrotic centers composed of fluid, semi- 
fluid, or caseous material. These centers are surrounded 
by fibrous tissue, the entire mass being made up of layer 
upon layer of fibrous lamellae. The end of the vas 
deferens will be found involved in the mass, to which it 
usually adheres firmly, or to the external surface of the 
wound, by dense fibrous tissue. This condition in the 




Fig:. 5.— ACTINOMYCOSIS. 

beginning may be identified by the tumefaction and 
particularly by the bad odor of the discharge. Later 
the large lesion is observed with the characteristic putrid 
discharge from the open wound. 

Treatment. — In the early stages the condition may 
be relieved by the energetic application of disinfectants, 
and if necrosis is present the excision or curettment of the 
necrotic centers. After the dense mass of fibrous tissue 
has formed, only the careful removal of the entire mass 
by operation is successful; and in this the greatest care 



122 



SWINE DISEASES 



must be exercised or the animal will bleed to death. 
The operative wound should receive the proper after- 
treatment. 

Botryomyces 

The Botryomyces ascoformans also infects castration 
wounds in swine. This condition is very common in 
certain localities at some seasons. It is of a chronic, 
insidious nature. The castration wounds may heal and 
be apparently normal, the first indication of the condition 




Fig. 6.— SCIRRHOUS CORD DUK TO B0TRY03IYC0TIC 
INFECTION. 

being a slight enlargement of the scrotum. The enlarge- 
ment persists and gradually increases in size until it is 
quite large; in some instances these masses may attain 
the size of a football. On examination of the affected 
pig a rather dense mass can be outlined, apparently 
adhered to the substructures but not attached to the 
skin unless the wound has failed to heal. These masses 
are found to be encapsulated with dense fibrous con- 
nective tissues. On sectioning the growth, many centers 
are found from one-half to two inches in diameter. 



THE URO-GENITAL SYSTEM 123 

These centers contain pus which may be caseous, and 
the various centers communicate by means of fistulous 
tracts. 

Treatment consists of ablation of the entire mass, 
which is ordinarily not difficult as the lesion is sub- 
cutaneous and is definitely circumscribed. 

Actinomycosis 

Actinomycosis may affect the scrotum of castrated 
swine, but is not common. 

Parasites 

Infestation of the castration wounds with screw- 
worms (larvae of the Campsomyia macellaria) are very 
common in the southern part of the United States. 
These larvae burrow into the tissues, thus mechanically 
injuring them and providing an avenue of entrance for 
various bacteria. 

Lesions. — The principal lesions consist of an active, 
acute inflammation with or without the production of 
pus. The surrounding tissues are tumefied, hyperemic, 
hemorrhagic, and contain the larvae. The extensive 
tumefaction developing within one or two days after 
castration is the most evident symptom. On a close 
inspection, larvae may be observed near or upon the 
surface, and by manipulation of the lesion larvae may 
be forced out upon the surface. In cases of screw-worm 
infestation there is a constant sero-sanguinous discharge 
that by attracting the female fly favors repeated rein- 
f est at ion. 

Treatment. — All that can be done in cases of screw- 
worm infestation is to support the strength and minister 
to the comfort of the animal and prevent a further 
infestation from the deposition of more eggs or larvae 
upon the wound and patiently wait for the investing 
larvae to reach the stage of development when they 
voluntarily leave the wound to pupate in the ground. 
This occurs in three to five days. 

The application of chloroform, naphthalene or other 
chemicals to the wound is worse than useless. Such 



124 SWINE DISEASES 

measures not only fail to effect the removal of more than 
a small percentage of the larvae, but they also irritate 
the highly sensitive tissues and greatly aggravate the 
condition. 

None of the ordinary fly-repellants has any deterrent 
effect upon the female of the screw- worm fly in the 
presence of fresh blood, either in recent wounds or in the 
discharge from screw-worm infested wounds. However, 
a mixture composed of turpentine one dram, phenol one 
dram and cottonseed oil four ounces is an effective re- 
pellent for this fly, and where there is a probability of 
screw-worm infestation it should be applied to fresh 
wounds and to infested wounds as long as the screw- 
worm larvse are present and the sanguinous discharge 
continues. One application daily is sufl&cient. 

Scrotal Hernia 

This form of hernia occurs in the male. It consists 
of a protrusion of omentum or intestine through the 
inguinal canal and into the scrotal sac. 

Scrotal hernia may be limited or extensive; in some 
instances the scrotum may be as large as a gallon jug. 
Raising the hind parts of the pig usually permits of a 
portion of the protruded structure passing back into the 
abdomen, and thus reduces the hernia. 

This condition is relieved only by operation in which 
castration is required if it has not been done previously. 
The covered operation is performed, and the vaginal 
tunic is supported by sutures. 

PENIS 

Malformations of the penis are rare. One case has 
been observed of a double penis, the organ being double 
from the ischial arch. Each penis contained a normal 
urethra, the two uniting at the arch and continuing to 
the bladder as a single urethra. 

Injury to the penis of barrows is rare, although 
incised wounds may sever this organ. The penis of 
boars may be injured by permitting breeding in quarters 



THE URO-GENITAL SYSTEM 125 

containing machinery or other places where injuries of 
various kinds may be inflicted. 

Preputial concrements or calculi sometimes occur in 
swine. They occasion difficulty in urination or even 
retention of urine and sometimes the urine accumulates 
in the sheath in considerable quantities. The accretions 
are easily detected by an examination and are not difficult 
to remove. 

The lining of the prepuce may be infested with screw- 
worms, which will occasion considerable swelling and 
distress to the animal. For the treatment see page 123. 
Preputial inflammation due to irritation from urine and 
infection sometimes requires care by cleansing and anti- 
septics. 

FEMALE REPRODUCTIVE ORGANS 

OVARY 

Malformations 

Malformations of the ovary are much more common 
than is generally suspected. The most frequent anomalies 
consist of changed position which ordinarily does not 
appear to interfere with the normal functioning of the 
organs. There may be two ovaries on one side and one 
on the other, or there may be two ovaries on each side. 
Either ovary may be exceptionally large or small, the 
other being normal in size. 

The ovaries may be injured, but this is rather the 
exception, owing to the thick body wall which serves as a 
protection. 

Hemorrhage 

Hemorrhage of the ovary may occur at the time of 
estrum, and is dependent upon the lacerating of a blood 
vessel when the graafian follicle ruptures. These hem- 
orrhages are of no practical or economic significance. 

Oophoritis 

This condition has been observed in sows, but princi- 
pally at abattoirs by veterinary inspectors. It is usually 



126 SWINE DISEASES 

secondary to metritis or salpingitis, though it may be 
metastatic or even primary. 

Lesions. — The affected ovary is enlarged, and, the 
surface being irregular, nodular projections of varying 
size occur. In the beginning the ovary is intensely 
red and cut surfaces bleed freely. The nodules repre- 
sent enlarged graafian follicles, which usually contain a 
gelatinous substance and sometimes blood. Latent 
suppurative centers may occur and may or may not be 
definitely circumscribed by a fibrous capsule. The con- 
dition may assume a chronic form, the ovarian structure 
becoming dense and hard due to the proliferation of 
fibrous tissue. 

Symptoms. — The principal evidence of ovarian 
inflammation is persistent sexual desire, and is manifested 
by excitement, frequent urination, and the search for a 
mate. 

Treatment. — ^Anodynes may be used to quiet the 
animal temporarily, and the blood supply may be diverted 
by means of a saline purgative or atropine in full physio- 
logic doses. Therapeutic agents are not at all certain in 
these cases, and if the patient is not especially valuable for 
breeding purposes, spaying is recommended. 

Cysts 

Ovarian cysts are quite common in sows. They 
probably have their origin from graafian follicles that 
have failed to properly mature. One or both ovaries 
may be affected. The cystic ovary may be uniformly 
enlarged or it may be lobulate4, the size attained being 
variable. Reyer reported a case in which an ovarian 
cyst was found weighing seven pounds. 

Lesions. — The affected ovary may contain either a 
single cyst or many cysts. The cyst may be ovoid, 
spherical, or lobulated. In those cases of multiple cysts 
the cysts sometimes communicate with each other or 
are multilocular. The cystic content may be a thin, 
limpid fluid, jelly-like, glue-like, bloody, or even caseous. 



THE URO-GENITAL SYSTEM 127 

Symptoms. — The symptoms presented by a sow 
affected with cystic ovaries are variable. There may be 
indigestion and circulatory disturbances, but the most 
common symptom is persistence of the estral period, the 
affected animals usuallj^ failing to conceive. 

Treatment. — Oophorectomy is the only apparent 
relief for cystic ovaries. If only one ovary is affected, 
the sow may still be used for breeding purposes. 

Dermoid and Dentigerous Cysts 

Dermoids and dentigerous cysts occur in the ovary, 
but are not of common occurrence in swine. 

Tumors 

Endotheliomas and sarcomas have been observed in 
the ovary of swine, but they are rare. They partake of 
the same nature as do these tumors occurring elsewhere 
in the body. 

FALLOPIAN TUBES 

Malformations of the fallopian tubes are not common. 
Injuries to the tubes may occur during the operation of 
spaying or cesarean section. 

An occasional case of pyosalpinx is observed in the 
carcasses of swine slaughtered at abattoirs. This con- 
dition is uncommon, and apparently of little clinical 
interest. 

UTERUS 

Malformations 

Malformations of the uterus are not significant 
because the majority of swine are fattened for market 
and are not used for breeding purposes. An occasional 
anomaly is observed, such as a rudimentary uterus, 
double uterus, atresia of the cervix, and so on. 

Injuries 

Injuries to the uterus are not common except in 
those animals that have had diflSculty in parturition and 
in which instruments have been used. In many instances 



128 SWINE DISEASES 

injuries produce no bad after effect, but occasionally they 
provide an avenue of entrance for infection of the peri- 
toneum and may result in fatal peritonitis. 

Hemorrhage 

Uterine hemorrhage in the sow is not of the same 
gravity as it is in the larger animals; however, its control 
is more difficult in the sow than in larger animals because 
of the small size of the uterus. 

Metritis 

Metritis is not so common in the sow as it is in the 
larger animals, or even in the sheep and goat. This is 
probably because of the fact that retention of the pla- 
centa is not so common in sows as in almost all other 
animals. The usual cause of metritis is infection, which 
ordinarily is a sequel to injuries, retained placenta, or 
dead fetuses. The sow appears to possess considerable 
resistance to uterine infection, for cases of metritis are 
relatively rare, and as further evidence of their resistance 
mummified fetuses are of common occurrence in sows. 

Metritis may be either purulent or septic. 

Purulent Metritis 

Purulent metritis is characterized by hyperemia and 
tumefaction of the uterine mucous membrane. Later 
there is desquamation of areas of the mucous membrane 
and accumulation of quantities of pus in the uterine 
cavity. Should the cervix become closed, there may be 
a marked distention of the uterus with the accumulated 
pus. The inflammation may extend into and involve 
the muscular coat of the uterus or even the serous mem- 
brane. In addition to the inflammatory lesions there 
may be lacerations and various other injuries. 

Septic Metritis 

Septic metritis is characterized by intensive inflam- 
mation involving in turn, as the disease progresses, the 
mucosa, muscularis, and serosa. The uterus usually con- 



THE URO-GENITAL SYSTEM 129 

tains a bloody, putrid fetus or fetuses, as septic metritis is 
most frequently a sequel of retention and putrefaction of 
the young. 

Prognosis should be guarded, as the disease is 
usually fatal. 

Symptoms. — Prostration and a purulent or putrid 
discharge from the vulva are the primary signs of septic 
metritis. There is inappetence, fever, and hyper- 
sensitiveness of pelvic region. 

Treatment. — Irrigation of the uterus and a washing 
away of the offending material is essential, but is attended 
with some difficulty in the sow owing to the small size of 
the genital organs. Hysterectomy has been advised but 
should not be practiced in those cases showing high 
temperature and prostration, and it is doubtful if it will 
prove successful in sufficient number of cases to justify 
its use. 

Tumors 

Various tumors, such as fibroma, myxoma, sarcoma, 
epithelioma, and carcinoma, have been observed in the 
uterus. The various tumors partake of the same general 
nature as the same type of tumor elsewhere in the body. 
Should an antemortem diagnosis be made, and the 
tumor found to be producing considerable injury, hys- 
terectomy is indicated. 

VAGINA 

Cloaca formation occasionally occurs in swine. This 
condition results from fusion of the rectum and vagina, 
there being but one external opening common to the 
uro-genital and digestive tubes. This deformity does 
not interfere with health, but it practically prohibits 
•breeding. Although it may be relieved by operation, 
the value of the animal usually does not warrant such 
procedure. 

Injuries to the vagina are occasionally infficted during 
parturition, but the condition is seldom recognized and 
rarely causes noticeable after effects. 



130 SWINE DISEASES 

Inflammation of the vagina usually accompanies 
metritis. The discharge in such cases is usually purulent 
and the condition is designated leukorrhea. Vaginal 
douches relieve simple cases of vaginitis, but if the 
primary disturbance is within the uterus it must be 
overcome before the vaginitis will yield to treatment. 

VULVA 

Although the location of the vulva predisposes it to 
injury, such mishaps are not common. 

Occasionally the Bacillus necrophorus infects the 
vulvar tissue and produces typical necrobacillosis, which 
may terminate fatally unless properly treated. 

MAMMARY GLANDS 

Although the mammary glands are modified glands of 
the skin, they are essential to the life of the newborn. 
Therefore, a discussion of the diseases liable to affect 
these glands belongs properly with the consideration of 
the reproduction organs. 

The location of the mammae of swine predisposes 
them to injury and infection of various kinds, and in 
addition the mammary gland contains a milk cistern which 
is also easily infected. But since swine are more resistent 
to infection than other domestic animals, the mammary 
disturbances also are less common in swine. 

Mammitis 

Acute inflammation of the mammary gland occurs, 
but is rare. The usual cause is infection, but this generally 
means that the gland has been injured and thus predis- 
posed to infection. 

The affected gland is tumefied, hot, and painful. 
On sectioning, varying quantities of milk and inflamma- 
tory exudate escape from the ducts. The blood vessels 
are gorged with blood, and the milk in the larger ducts 
and cistern contains clots. 

The affected sow refuses to allow her pigs to nurse. 
She will change position as frequently as they attempt 



THE UROGENITAL SYSTEM 



131 



it, and occasionally a sow is observed that will purposely 
injure the pigs if they persist in their endeavor to nurse. 
On examination, the gland is found enlarged, more 
sensitive than normally, and if any milk is forced out of 
the teat it will be more or less rojw. 

Treatment. — Hot and cold applications alternated, 
when possible to apply such treatment, will be of as 




I iff. 7.— INFECTION OF MAMMARY GLAND. 
Normal fflandular tissue. B. Calcified areas. C. Galactophorous 



much value as any local treatment. The administration 
of a purgative is also advised. 

Botryomycotic Mammitis 

Botryomycotic mammitis occurs in swine, but is 
not common. The lesions are practically the same as 



132 SWINE DISEASES 

those described for botryomycosis under the heading 
''Sequels of Castration," on page 122. Prognosis should 
always be guarded in those cases in which the mammary 
gland is removed, as a large percentage of the animals 
die. 

Actinomycotic Mammitis 

i\.ctinomycotic mammitis, in the experience of the 
writer, is more common in swine than botryomycotic 
mammitis. Infection occurs through abrasions of the 
skin surface. This condition is most common in swine 
that are in pasture in stubble fields. The lesions are the 
same as lesions of actinomycosis of any soft tissue and 
consist of a dense surrounding capsule of fibrous tissue 
inclosing multilocular communicating centers containing 
a tenacious, granular, creamy -white pus. The actinomy- 
cotic tumefaction may become eroded and the tyical 
actinomycotic pus discharged. Actinomycotic mam- 
mitis is characterized bj^ the presence of the tumefaction, 
which may be round and have a smooth surface or it 
may be lobulated. These tumefactions vary in size 
from that of a small marble to masses larger than a 
baseball. 

Ablation of the entire tumor is the most rational 
and successful manner of combating and relieving this 
trouble. 

Tuberculous Mammitis 

Tuberculous mammitis is relatively common in 
swine. The infection of the mammae may be due to a 
diseased condition elsewhere in the body or it may be 
introduced through wounds from the outside. 

The lesions are the same as other tuberculous lesions. 

Treatment. — If the infection is localized in the 
mammae the disease may be successfully treated by 
operation, but the safest and most sanitary plan is 
destruction of the animal and cremation of the carcass, 
thereby diminishing the possibility of spreading the 
infection. 



THE UROGENITAL SYSTEM 133 

Tumors 

Mammary tumors are rare in swine, though an 
occasional papilloma may be observed upon the teat. 
Rarely do adenomas occur in the mammae of swine, 
although a few cases have been reported. 



SECTION IV 
ORGANS OF LOCOMOTION 



UNDER this heading will be considered the dis- 
eases of the voluntary muscles, bones, and joints. 
A great variety of malformations of the organs 
of locomotion have been observed in swine. Multi- 
plicity of legs or duplication of portions of a leg are 
relatively common, and fusion of parts ordinarily separate 
is occasionally encountered. These abnormalities may 
be so adverse to the existence of the animal that it dies 
soon after birth, or the anomaly may be so slight that 
the animal is in no way inconvenienced and develops 
into maturity. 

Injuries of various kinds are prone to damage and 
possibly destroy the usefulness of the part affected, and 
thus interfere with the locomotion of the animal to such 
an extent that it must be sacrificed. Muscle wounds 
usually give little trouble in swine because of their 
marked resistance to infection, while fractures are not 
so troublesome in swine as in the larger animals, and are 
usually repaired rapidly and frequently without inter- 
vention of the surgeon. 

Sore Feet 

The feet of swine that are kept on pavements or driven 
long distances over hard roads become sore. This con- 
dition is attracting the attention of serum producers 
who are required by the government regulations to keep 
the hyperimmune swine on concrete or other similar 
floors. Those producers depending upon tail bleeding 
are having considerable difficulty in keeping the hyper- 
immune swine for the required time because it is difficult 
to keep the pens free from filth when bedding is used. 

135 



136 SWINE DISEASES 

Sore feet due to rough, hard roads and pens also 
occasion some trouble in swine. This condition caused 
more concern in former times, when swine were driven 
considerable distances to market, than at the present 
time. However, it also is a problem that confronts the 
serum producers. 

About the only treatment is to provide ample, clean 
bedding or turn the swine out to pasture. 

Fatty Degeneration 

Fatty degeneration of muscle tissue has been observed 
in suckling pigs by various investigators. This disease 
or condition is characterized by an extensive fatty 
degeneration of the muscular tissue of the entire body. 
The cause of this degeneration is not known, although 
it may be a sequel of inbreeding. It affects pigs from 
a few days old to three or four weeks of age. The muscle 
has a white appearance, as if it had been cooked. Similar 
changes may also be noted in the lymph glands, liver, 
and kidneys. The affected pigs cease to nurse, lie on 
the ground, are weak, and may have diarrhea. The 
disease almost always terminates fatally, the pigs some- 
times not even struggling when they die, but in other 
instances convulsions precede death. Thus far no 
medicinal treatment has proved of value, but the disease 
may be prevented by proper care and the frequent 
introduction of new breeding stock. 

Muscular Rheumatism 

Rheumatism may affect the muscular tissue, but 
more frequently it affects articulations in swine. 

The cause of muscular rheumatism has not been 
positively identified. No doubt undue exposure predis- 
poses the animal to this condition, but there must also be 
some active cause, such as infection or absorbed injurious 
chemical substances. 

Lesions. — Muscular rheumatism primarily affects the 
connective tissue of the muscles. The lesion consists of 
a serous or hemorrhagic infiltration between the muscle 



ORGANS OF LOCOMOTION 137 

bundles and fibers, and rarely of necrosis of the intra- 
muscular fibrous tissue. The muscle fibers are affected 
with parenchymatous or fatty degeneration, and the 
surrounding arterioles and capillaries are engorged. 

Symptoms. — ^The principal symptom consists of 
expression of pain, especially evident when the animal 
moves. Locomotion is interfered with, and there is a 
shifting lameness. Some cases of so-called paralysis 
resulting in dragging of the hind legs are probably mus- 
cular rheumatism. If the disease is sufficiently extensive 
the affected animals refuse to eat. Muscular rheumatism 
is differentiated from trichinosis by the periodic shifting 
lameness of rheumatism and by the general absence of 
systemic disturbances. It may be necessary to dis- 
tinguish it from rickets, which is not difficult, since the 
latter is a disease affecting the bones. 

Treatment. — Provide good quarters where the animal 
will not experience wide variations of temperature within 
a short time. Laxatives and some form of salicylates or 
their derivatives are usually of value, but must be given 
judiciously to avoid impairment of digestion. 

Articular Rheumatism 

Articular rheumatism sometimes occurs in swine. 
This condition affects swine that have been unduly 
exposed, but probably the exciting cause is infection. 

Articular rheumatism is essentially an inflammation 
of the periarticular structures, including the synovial 
membrane. The inflammation may be serous, fibrinous, 
or hemorrhagic, and in extreme cases it may become 
purulent. The exudate is accumulated in the peri- 
articular structures and occasionally in the joint cavity. 
Thj synovia become admixed with the inflammatory 
exudate and appears turbid, bloody, or purulent, and 
may contain coagulated fibrin; the articular surfaces are 
rough. In cases of long standing the articulation is 
surrounded by varying quantities of fibrous tissue which 
may cicatrize and cause deformity. Various articulations 
are affected, but the lesions are principally confined to 
the carpal, tarsal, stifle, and fetlock joints. 



138 SWINE DISEASES 

Symptoms. — The onset of this trouble is sudden. 
The affected articulations become swollen and are very 
sensitive to palpation; the animal refuses to place weight 
on them or, if compelled to do so, expresses pain. If 
articulations of more than one leg are simultaneously- 
affected the animal remains lying down, arising only 
after considerable urging. There is usually some rise of 
temperature and a diminished desire for food, or inappe- 
tence. The disease runs a variable course, the attacks 
being intermittent. An attack usually continues for 
about two weeks, then the animal apparently recovers, 
but sooner or later the attacks reccur. 

Treatment. — The treatment for articular rheumatism 
is practically the same as for muscular rheumatism. 
Provide good quarters, and administer laxatives and 
salicylates. The outcome of the disease is uncertain, 
and if the animals are in butcher condition they should 
be disposed of several days after the cessation of the 
symptoms of an attack. 

Rickets or Rachitis 

This is essentially a disease due to some disturbance 
of metabolism, but since the lesions are manifested 
principally in the bones it may be considered in this 
chapter. 

Rickets is relatively common in swine, and is confined 
principally to young pigs. The disease is more prevalent 
in some localities than in other sections of the country, 
and the condition appears to prevail more extensively 
during some years than others. 

Etiology. — The specific exciting cause of rickets is 
unknown. The condition is due to an insufficient deposit 
of lime in the bone. It may be due to an insufficient 
lime in the food, to intoxication which may neutralize or 
prevent the deposit of lime in the bone, or infection may 
be a causative factor. 

Lesions. — The condition is not confined to any 
particular type or group of bones; however, the lesions 
are usually most pronounced in the long bones of the 



ORGANS OF LOCOMOTION 139 

legs, which are bent or curved, the animal being "bow 
legged." The bones are soft and so spongy that they 
may be cut readily with a knife. The epiphyses of the 
long bones are enlarged and irregularly club-shaped, 
while the shaft is also irregularly thickened. There is 
a subperiosteal, spongy layer. The yellow marrow is 
red in color and is of a gelatinous consistency. There 
may be ulceration of articular surfaces, and the flat 
bones of the cranium and pelvis may be thickened and 
rarefied. The nares and mouth may be practically 
obliterated by the enlarged rarefied nasal bones and 
hard palate; the teeth may appear deep-set on account 
of the tumefaction of the alveolar tissue. In advanced 
cases, lesions may be found elsewhere causing disturb- 
ances of the digestive or respiratory system. 

Symptoms. — The first evidence of the disease is 
weakness, diminished or depraved appetite, and diarrhea. 
But lameness or stiffness of gait succeeded by bending 
or arching of the bones is the first positive indication of 
rickets. At this stage the lying posture is almost con- 
tinuously assumed. When the affected animals are 
made to arise they complain of pain by grunting and 
squealing, and not infrequently they will walk on the 
carpal joints. There may be nervous disturbances 
evidenced by dizziness, somnolence, and convulsions. 
As the disease progresses the enlarged epiphyses become 
evident and appear as a swollen condition of the articu- 
lation. Similar bony enlargements may also occur 
elsewhere. The bulging of the long bones of the front 
legs exert undue pressure upon the ribs, which results 
in disturbed respiration, and the vertebral column is 
variously curved, upward, downward, or laterally. 

This disease is of a chronic nature and continues for 
months unless death intervenes early, which is exceptional. 
Diagnosis is not difficult after the changes in the bones 
are evident, while the chronic nature of rickets is sufficient 
to differentiate this condition from articular rheumatism. 
Tuberculous osteitis is differentiated from rickets by the 



140 SWINE DISEASES 

limited infection and the less extensive tumefaction, and 
lack of density of the affected bones. 

Treatment. — Treatment of rachitic swine is advised 
only in the early stages of the disease. Those in the 
advanced stages should be destroyed. The first thing to 
do is to place the animals in sanitary quarters, then 
medicinal treatment consists of administering lime in 
some form. Prepared chalk may be used. Bone meal 
is also of value, precipitated calcium phosphate is highly 
recommended by some, and calcium chlorate may be 
found serviceable. Preventive measures, as proper feed- 
ing and care, practically insure against the occurrence of 
this disease in swine. 

Osteomalacia 

This is a disease characterized by softening and 
fragility of bones. Osteomalacia is also a disease of 
disturbed metabolism which evidences itself by lesions 
of the bones. It is not of common occurrence in swine, 
and when found is due to an insufficient amount of lime 
in the regimen, in a form capable of assimilation. 

The bones most frequently involved are those of the 
extremities, ribs, vertebral column, skull, and pelvis. 
The affected bones become enlarged and less dense, the 
marrow cavity of long bones is increased in size and 
filled with a gelatinous, usually hemorrhagic marrow, 
while the osseous tissue is less dense and more fragile. 
Fractures are very common. 

The disease is usually initiated by digestive dis- 
turbances, which is succeeded by emaciation, impaired 
and usually difficult locomotion, fractures, and various 
deformities. The disease finally assumes a chronic 
form, evidencing periods of temporary improvement and 
relapses. This is essentially a disease of mature animals, 
and this factor is of value in differentiating osteomalacia 
from rickets. The prognosis is favorable in cases showing 
no marked enlargement of bones or deformity, and 
unfavorable in those cases showing deformity. 



ORGANS OF LOCOMOTION 141 

Treatment. — Provide proper food and surroundings, 
and administer lime salts, as outlined in the foregoing 
for rickets. 

Purulent Osteomyelitis 

Inflammation of the bone marrow occurs in swine. 
This condition is sporadic, and is most frequently ob- 
served in young animals. 

Etiology. — Purulent osteomyelitis is caused by infec- 
tion. Various pyogenic microorganisms have been identi- 
fied, such as Staphylococcus pyogenes aureus and albus. 
Streptococcus, and in one instance the Bacillus pyocy- 
aneus, was isolated and apparently occurred in pure cult- 
ure. There is probably some predisposing cause, such as 
hog cholera, but all of the cases observed have shown no 
lesions of cholera or other than the primary disease. 

Lesions. — The ribs are most frequently affected. 
The bone marrow becomes hyperemic and invaded with 
leukocytes and inflammatory products, and the internal 
pressure causes the bone to become enlarged and the 
marrow cavity to be increased in size. The marrow and 
the inflammatory exudate disintegrate and form pus. 
As pus is produced the bone becomes larger and round, 
although it may show some irregularities in shape. The 
pus in the marrow cavity may erode the bone tissue and 
discharge, thus producing a fistulous tract, but more 
frequently the pus becomes caseous and may later 
undergo calcification. Suppurative processes are rarely 
observed in other bones. 

Symptoms. — ^There is little outward manifestation 
of purulent osteomyelitis other than the formation of a 
barrel chest (the ribs form a wider arch, the thorax 
appearing almost round in cross-section), and the promin- 
ent tumefied ribs. If the affected animal is in good con- 
dition the ribs are not visible. These cases are usually 
of long standing, and the disease is essentially chronic. 
Antemortem diagnosis is rarely made. Purulent osteo- 
myelitis can be distinguished from osteomalacia by the 
localization of the process in the ribs. 

Treatment. — Medicinal treatment is of no value. 



142 SWINE DISEASES 

Trichinosis 

Trichinosis assumes two forms, intestinal and mus- 
cular. Both types occur in the same animal, the intestinal 
preceding the muscular form. 

This disease is quite prevalent, particularly in North 
x\merica. From two to eight, per cent of American 
hams imported into Germany have been found infested. 
The disease is less prevalent in Europe, or at least the 
statistics so indicate. 

The cause of trichinosis is the Trichinella spiralis. 
This is a small, round worm, the adult rarely exceeding 
one-twelfth of an inch in length. The life cycle of the 
parasite is as follows: 

The larvae gain entrance to the digestive tract in 
meat, where the surrounding capsule is dissolved by the 
digestive juices, and thus are liberated within twenty- 
four hours. They pass into the small intestine, where 
they become sexually mature in about three days. About 
five days after copulation, or within ten or twelve days 
after ingestion, the pregnant female and the male are 
found in the crypts of Lieberkiihn and the female begins 
to deposit her young in the form of living embryos. 
This process is continued by the female for from six to 
ei^t weeks, during which time she produces from eight 
to fifteen thousand young. A few of the embryos pass 
out with the feces, but most of them pass through the 
tissue of the intestine, some of them gaining entrance to 
capillary lymph and blood vessels, while others wander 
through the tissue. Those passing into the lymphatics 
ultimately reach the blood stream, as do those passing 
directly into the blood capillaries, and finally they are 
distributed by the blood or by direct migration to all 
parts of the body. The embryos thus distributed pass 
into various tissues, but as a rule only those entering 
the muscular tissue survive and develop. The embryo 
matures into a larva in the muscle in a period of about 
two months; by this time the irritation produced has 
resulted in the formation of a capsule. These encapsu- 
lated larvae will retain their vitality in swine for a period 



ORGANS OF LOCOMOTION 143 

of about eleven years, but the capsule and some of the 
interior of the cyst undergo calcification, the process 
beginning about one or one and a half years after encap- 
sulation. 

Swine become infested by eating trichinous flesh of 
pigs, rats, or other animals, or from eating the excretions 
of infested animals. All breeds of swine, regardless of 
age, are equally susceptible. Trichinosis is most preva- 
lent in swine kept in small pens, especially when sani- 
tation is not observed. 

Lesions. — The adults produce an intestinal catarrh 
which is most evident in the proximal portion of the in- 
testine. Soon after the embryos begin to migrate the 
mesenteric lymphatic glands become enlarged, and there 
may be pulmonary congestion and parenchymatous 
degeneration of the liver and kidneys. The affected 
muscle^first becomes swollen, and appears of a gray color. 
About eight weeks after the embryos begin to migrate, 
small gray or grayish-white specks may be detected in 
the muscle tissue. This condition is especially evident 
in the diaphragm, intercostal muscles, muscles of the 
cervical region, and tongue. If the lesions are of long 
standing they will contain calcium salts, which may be 
detected as small, gritty masses. Microscopically, in 
the first year of muscular trichinosis the larvae can be 
readily detected as small, coiled, thread-like worms 
within a capsule. 

Symptoms.— Clinical trichinosis has been observed 
only in experiments, or at least the disease has not been 
recognized by the clinician. Experimentally, intestinal 
trichinosis becomes evident in from three to six days 
after infestation. The disease is manifested by the 
following symptoms: inappetence, vomition, diarrhea, 
colic, arched back, unwillingness to move, and rapid 
emaciation. Evidence of muscular trichinosis appears 
in about two weeks, and is manifested by the following 
symptoms: rubbing against posts or other objects, 
stiffness, assumption of the lying posture the greater 
part of the time, dyspnea, dysphagia, and rise of tem- 



144 SWINE DISEASES 

perature. These symptoms, in the order mentioned, 
continue for four to six weeks, and the affected animal 
apparently recovers. Diagnosis of trichinosis may be 
possible clinically, but the absolute diagnosis depends 
upon a miscroscopic detection of the parasite. 

Treatment. — Medicinal treatment may be of some 
value in eliminating the adults from the intestine, but 
the disease is rarely diagnosed before death. The 
muscular form of the disease is not relieved by treatment. 
Prophylactic measures, such as general sanitation and 
eradication of rats, should be instituted. 

Cysticercosis (Measles) 

Cysticercosis is a condition due to the invasion and 
developemnt of the cystic form of a tapeworm. This 
condition prevails more or less in the swine of practically 
all countries. Cysticercosis in the muscular tissue of 
swine is due to the cystic form of the Taenia solium; the 
cystic form of this parasite being designated Cysticercus 
cellulosse. 

Etiology. — The life cycle of the Taenia solium is as 
follows. The ova of the adult, which resides in the 
intestinal tract of man, is eliminated in the feces. Swine 
eat the contaminated feces and the digestive juices 
dissolve the shell of the tapeworm ova and liberate a 
six-hooked embryo. The embryos bore through the walls 
of the stomach, some of them entering the blood vessels, 
and are thus distributed by migration and the circulation 
of the blood to all parts of the body. Those depositing 
elsewhere than in the muscular tissue do not as a rule 
develop. The development of the parasite is rather 
slow. The embryo assumes the form of a cyst and in 
twenty days' time is about the size of an ordinary pin- 
head. By this time the head of the future tapeworm is 
visible as a mere point. About two months after the 
embryo lodges in the muscle it has attained the size of a 
small pea, and in three months the embryo has matured, 
as is evidenced by the presence of sucker disks and a 
rostellum of booklets on the head of the future tapeworm. 



ORGANS OF LOCOMOTION 



145 



Should a human being consume uncooked swine flesh 
containing one of these mature bladder worms the 
digestive juices would dissolve the capsule and liberate 
the scolex, which would attach itself to the intestinal 
mucosa. From three to five months are required from 
the time of ingestion of the bladder worm by the human 
until ripe segments are eliminated. One ripe segment 
contains from ten to thirty thousand ova. 




Vig. 8.— CYSTICKKCOSIS (Pork Measles). 
A. Muscle. B. Fat. C. Cysticercus cellulosae. 



Swine become infested by ingesting water or food 
contaminated with the ova of the Taenia solium. This 
condition occurs only in hogs that consume human 
excrements, and young swine are more susceptible to 
this condition than are the aged animals. 

Lesions. — The presence of the cysts typifies Cys- 
ticercus cellulosae. These cysts vary in size from visible 
points to small beans. They are usually oval in shape, 



146 



SWINE DISEASES 



and the scolex can readily be recognized within as a white 
point or body. The cyst is surrounded by a thin capsule 
and contains one head and a thin, watery fluid. iVfter 
the cyst has persisted for one year or longer it degener- 
ates, the content becoming purulent, and later calcifying. 
Symptoms. — Cysticercosis in swine is rarely recog- 
nized clinically. The migration into and irritation of 




Figr. 9.— I'EDUNCUT^ATED FIBROMA. 



the muscle may cause muscular soreness and disturbed 
locomotion which, depending upon the extent of the 
invasion, may be associated with inappetence, unthrifti- 
ness, and emaciation. 

Treatment. — Prophylaxis consists of preventing con- 
tamination of swine food and water with human excre- 
ments. No curative treatment is available. 

Sarcosporidiosis 

Sarcosporidiosis is a disease of nuiscular tissue due 
to a parasite, the Sarcosporidia. This condition is rela- 
tively common in swine. Generally speaking, sarcos- 
poridiosis is not considered a disease of any importance, 
but frequently swine are affected with a weakness of the 
muscles of the back that causes them to drag the hind 



OllUANS OF LOCOMOTION 147 

legs. Although no opportunity for the examination of 
the muscle from these cases has arisen, the writer has 
thought the condition is probably due to sarcosporidiosis. 
Etiology. — The Sarcoeystis miescheri is the cause of 
sarccsporidiosis. The exact life cycle of this parasite is 
unknown. 

Lesions. — The cysts are usually' so small that they 
cannot be detected without the use of a microscope. 
However, an unusual specimen was obtained by York 
at an abattoir in Chicago in which the cysts could be 
readily detected as grayish-white ovoid patches. Micro- 
scopically, the parasites are found within the muscle 
sarcolemma. They appear to destroy or displace the 
muscle substance, the fiber being entirely severed, the 
sarcolemma alone remaining intact. The sarcocysts 
contain many round or oval bodies, the sporozoites. 
The cysts undergo degeneration and calcify, but at 
what age these changes occur has not been determined. 

Symptoms. — The disease has not been recognized 
clinically, but no doubt infestation would interfere with 
the muscle function. 

Treatmient. — Therapeutic treatment is not available, 
and in the absence of a definite knowledge of the life 
cycle of the parasite, preventive measures are only 
problematic. General sanitation should be maintained. 

Tumors 

An occasional tumor is encountered that has invaded 
the muscular or osseous tissue of swine. But, generally 
speaking, tumors of these structures are of little signifi- 
cance. 



SECTION V 



THE SKIN 

DISEASES of the skin are probably not so common 
in swine as in other domestic animals. Because 
of the location of the skin it is subject to a 
variety of injuries of various kinds, but fortunately 
swine are not very susceptible to wound infections and 
therefore cutaneous lesions heal promptly and with 
little inconvenience to the afflicted animal. 

Erythema 

Erythema is a name applied to the condition resulting 
from congestion of the skin. It is quite common, par- 
ticularly in swine having little or no pigment in the skin. 
It is also a common condition in some infectious diseases, 
such as swine plague and hog cholera. 

Etiology. — Simple erythema in swine is most fre- 
quently the result of sunshine but may be due to contact 
with some irritant. In some instances erythema may 
be caused by ingested chemicals that have a special 
selective action on the skin or are eliminated by the skin. 

Lesions. — Engorgement of the superficial vessels 
and redness are the only demonstrable lesions. 

Symptoms. — Redness, and perhaps pruritis, are the 
principal symptoms. 

Treatment. — Remove the cause, and the disturbance 
will cease to exist. 

Sunburn 

Swine having little pigment in the skin are injured 
by sunlight. In some sections it is not profitable to 
raise white pigs because of the irritation of the skin by 
the sun and the production of dermatitis. 

Sunburning is a type of dermatitis characterized by 
erythema, tumefaction, and desquamation of the super- 

149 



150 SWINE DISEASES 

ficial layers of the epidermis. In long-continued cases 
the skin becomes thickened, due to the formation of 
fibrous tissues. Swine affected with dermatitis do not 
thrive, and they evidence a harsh skin and bristly coat. 
Treatment. — The treatment of these cases is simple, 
as about all that is required is to shield the animals from 
the direct light of the sun. Should the inflammatory 
process be well marked, cooling antiseptic solutions may 
be applied. 

Freezing 

Pigs farrowed in midwinter in the northern portion 
of the temperate zone, where not properly housed, are 
frequently frozen. The ears and tail are most affected 
because of the large surface exposure and distal location 
where the circulation is diminished. In some instances 
the tissues are destroyed by the low temperature, and 
slough, while in other cases the ears or tail, or both, are 
frosted only and an inflammatory reaction is established 
resulting in an engorgement and tumefaction of the 
part. Later the skin desquamates and the parts are 
tender when palpated. 

Transportation of market hogs in open stock cars 
during very cold weather is responsible for the freezing 
of the surface skin. The skin sometimes evidences 
the lesions in strips corresponding to the openings between 
the boards on the car. The lesions are similar to those 
described in small pigs. 

Treatment. — This consists of protection against 
furthur freezing and the local application of protectant 
dressings, as in ordinary wounds. 

Hemorrhage 

Cutaneous hemorrhage in which the extravasate is 
retained in the skin is relatively common but is practically 
always associated with specific infective diseases, seldom 
occurring as simple cutaneous hemorrhage. 



THE SKIN 151 



Urticaria 



Urticaria is a skin disease characterized by the forma- 
tion of pruritic wheals. It is not common in swine and 
when occurring is usually found in young pigs. 

Etiology. — Urticaria is of systemic origin. It is 
usually associated with digestive derangement, but may 
be caused by filth and the irritation caused by lice. 

Lesions and Symptoms. — The typical lesions are 
red, circumscribed blotches that are hot and pruritic. 
Because of the pruritis the pig rubs the skin and may 
produce abrasions from which serum and blood may 
escape. The disease usually terminates in recovery on 
the second or third day, although in severe cases pustular 
formation may follow. 

Treatment. — Clean the swine and the premises, and 
administer a saline purgative, such as Epsom salt. 

Eczema 

Eczema is an inflammation of the skin characterized 
by multiform lesions. Though this disease occurs in 
swine, it is not very prevalent. 

Etiology. — Eczema in swine is apparently a disease 
of filth. Weak, anemic pigs are much more susceptible 
than strong and otherwise healthy animals. The specific 
exciting cause is not known. 

Lesions and Symptoms. — Typical eczema is char- 
acterized by the following lesions, which occur in the 
order mentioned: erythema and papulovesicular eruption, 
which may or may not be succeeded by the formation of 
pustules. The contents of the vesicles and pustules 
become desiccated and accumulate, thus forming scabs. 
There is pruritis practically throughout the entire course 
of the disease. As the disease progresses the skin becomes 
thickened, leathery, and cracks, the crevices or rhagades 
extending deeply and from which more or less blood 
escapes. 

Eczema is differentiated from parasitic dermatitis by 
the absence of the parasites. It is essentially a chronic 



152 



SWINE DISEASES 



disease; there may be repeated attacks. The disease as 
a rule is not fatal in swine. 

Treatment. — Remove all influences that predispose 
to the condition. Prevent injury from rubbing. Topical 
application of soothing agents may be used, but their 







Fig:. 10.— EI^EPHANTIASIS. 
A. Granular papiUoinatous, depilated areas. B. Khagades or 

crevices. 

value is doubtful. See that the animals obtain and 
digest their food properly. A good, brisk purgative 
occasionally will be of value. 

Dermatitis Granulosa 

A granular skin eruption has been identified in swine. 
The condition occurs in patches on the ears, back, and 
croup, and is probably infectious. 

This condition has responded quickly to treatment 
with antiseptics. 



THE SKIN 153 

Necrobacillosis, Actinomycosis 

Necrobacillosis is a very common cutaneous disease 
in swine. Cutaneous actinomycosis and tuberculosis 
occur less frequently. These conditions of the skin will 
receive consideration under the special topics of necro- 
bacillosis, actinomycosis, and tuberculosis, in Section 
VIII. 

Tumors 

Pigmented moles are of frequent occurrence in the 
skin of swine. These moles are sometimes pigmented 
with melanin, and when interfered with develop into 
malignant melanosarcomas. Many pigmented papil- 
lomas and papillo-fibromas are also encountered in the 
skin of swine, while multiple fibromas have been observed, 
they are not at all common. More rarely have primary • 
or even secondary carcinomas and epitheliomas been 
recorded as cutaneous tumors in swine. 

Parasites 

Swine harbor many cutaneous parasites, some of 
which are exceedingly detrimental to the health of the 
animals. 

Of the dipterous group one only, the Campsomyia 
macellaria (screw-worm), requires special mention. In 
some sections these parasites cause considerable damage 
and some fatalities. The larvae only are parasitic, the 
adult female depositing the ova in wounds or damaged 
tissue. The ova hatch in from one to ten hours and 
immediately begin to burrow into the surrounding 
tissues. The fully developed larvse are about one- 
half of an inch long and about one-third the diameter 
of a lead pencil. The damage consists not only of 
mechanically lacerating the tissues but also of carrying 
infection into the surrounding tissues. The larvse 
remain in the tissue from four to six days, then drop to 
the ground, where they undergo the pupal metamor- 
phosis. 

The time-honored treatment consists of curetting the 
wound, thus removing all the larvse possible. It may be 



154 SWINE DISEASES 

necessary to apply chloroform or some penetrating anti- 
septic to cause the larvae in the deeper tissues to migrate to 
the surface, or at least to move energetically in order that 
they may be located and removed. The wound should 
be properly dressed and protected against future infesta- 
tion. It is always well to observe the wound on the 
second day to make certain that all larvae have been 
removed. However clinicians report that this line of 
treatment is wholly ineffective, claiming better results are 
obtained from the treatment for screw-worm in festation 
given on page 123. 

Flea Infestation 

Representatives of the order, Siphonaptera, constantly 
inhabit hog houses and pens in some sections of the 
country. These parasites are blood suckers and obtain 
their nourishment directly from the swine, but do not 
appear to cause any serious trouble. No doubt they 
produce some irritation where they pierce the skin, and 
swine thrive better in their absence. Fleas breed 
in filth, the ova being deposited in fecal matter or 
other filth. The larval and pupal stages also take place 
in filth and in the soil, the entire cycle from adult to adult 
requiring about one month. 

Fleas may be lessened in number and ultimately 
eradicated from most premises by persistent cleanliness 
and by dipping the swine in some standard dip every 
ten days for a period of six weeks. 

Lousiness (Phthiriasis) 

Phthiriasis, or lousiness, is the most common para- 
sitic disease of swine. The hog louse, Hematopinus suis, 
is a blood-sucking louse and one of the largest of known 
lice. The adult ovigerous female cements the ova on 
the hair behind the ears, in the flank region, and else- 
where. The ova hatch into small lice in from ten days 
to two weeks. These lice do damage by direct abstrac- 
tion of blood and by irritation of the skin, which causes 
more or less of pruritis. This makes the swine restless 



THE SKIN 155 

and, not receiving their proper rest, they probably do 
not do as well as they otherwise would. 

It is not a difficult matter to eradicate lice, but their 
permanent elimination from swine entails continued 
vigilance. Where large numbers of swine are infested 
the most economical plan is to put in a dipping vat 
and dip the hogs every ten days for three or four 
dippings. In the meantime the sleeping quarters 
should be cleaned and dipping solution used here 
as a spray. If there are only a few swine to treat, 
hand dressing with some standard dip is the most eco- 
nomical method of treating them, of if the swine have a 
tank or place where they wallow, some dipping solution 
may be placed therein. The swine thus dip themselves 
and destroy the lice. 

The rubbing post has been used with fair success as a 
means of holding louse infection in check. One or more 
posts are set in the pens and ropes wound tightly around 
them for a distance of two feet from the ground. These 
ropes should be moistened with crude petroleum from time 
to time. The swine will annoint themselves and destroy 
most of the lice by rubbing themselves against these posts. 

Mange 

Mange, or infestation of swine with some Acari or 
mange parasites, is not a rare condition in this country, 
where two forms of mange occur — sarcoptic mange and 
demodectic mange. 

Sarcoptic Mange 

Sarcoptic mange is enzootic in certain sections. It is 
caused by infestation with the Sarcoptes scarbiei, var. 
suis. The life cycle of this parasite is as follows: 

The ovigerous female burrows into the skin, forming 
galleries in which she deposits her eggs, usually about fifteen 
in number. The ova hatch in from five to ten days into 
six-legged asexual larvae which may remain in the gal- 
leries or pass out under the scabs, and in two to three 
days moult into nymphse. The nymphse have four 



156 SWINE DISEASES 

pairs of legs, but they have no sexual organs. In two or 
three days the nymphse moult and the sexually matured 
males and females come forth. The sexually matured 
parasites mate, and in about three to five days the 
ovigerous female is found in the gallery in the skin, 
ovulating. Thus the entire life cycle does not exceed 
twenty-five days, and under the most favorable condi- 
tions may be accomplished in fifteen days. From each 
ovulation about five males and ten females are produced, 
and if the reproduction were to go on unhindered for three 
months, the total reproduction would approximate 
1,500,000 parasites. The adults are mere specks, barely 
visible to the unaided eye. 

Swine become infested from infested premises or from 
infested swine. Premises may remain infested for six 
months or even longer. 

Lesions. — The lesions produced by the Sarcoptes 
are practically confined to the skin; however, secondary 
lesions, as emaciation, may arise. The parasite obtains 
tissue juice by pricking the skin with its stylet. The 
stylet injury produces erythema, succeeded by the forma- 
tion of vesicles, which rupture, the vesicular fluid drying 
and forming a scab beneath which the parasites are 
found. Scabs are of varying thickness, and accumulate 
wherever the parasites are found unless the affected ani- 
mal rubs them off. Galleries are formed within the skin, 
and this also adds to the irritation. The accumulated 
dry scabs break and damage the hair more or less, which 
falls, leaving the parts affected practically hairless. The 
irritation causes inflammation, and this results in fibrous 
proliferation and thickening of the skin. The thickened, 
leathery skin loses its pliability and becomes fissured or 
cracked. In long-continued cases the animals become 
emaciated. 

Symptoms.— Intense pruritus, especially around the 
ears and eyes, and the finding of papules, vesicles, and 
scabs are the first evidences of scabies. Later there is 
depilation and thickening of the skin, with the accompany- 
ing rhagades. The disease will probably affect all the 



THE SKIN 157 

swine that have been kept in one lot. The finding of the 
parasite is positive evidence upon which to base a diag- 
nosis. 

Treatment. — Sarcoptic mange may be successfully 
treated by the use of the lime and sulphur dip or nicotine 
dip, repeating every ten days for three dippings, 
provided that the quarters are cleaned and disinfected 
and the thick scabs are removed so that the dipping solu- 
tion may gain access to the parasites. Some old chronic 
cases do not respond readily, if at all, to treatment because 
of the thick, wrinkled skin which protects the parasite. 

Demodectic Mange 

Demodectic or red mange is not so prevalent in swine 
in America as is sarcoptic mange. Red mange rarely 
occurs enzootically. 

The cause of red mange is the Demodex folliculorum, 
var. suis. This parasite is not visible to the unaided eye. 
Microscopically, it is found to be similar in shape to an 
oat grain and has four pairs of short legs. The life cycle 
of this parasite is practically the same as of the Sarcoptes 
scarbiei, var. suis, except that the ova are deposited in a 
pustule in the hair follicles and sebaceous glands instead 
of in intradermal galleries. 

Lesions.- — The skin of the legs of swine is most fre- 
quently affected. The parasite gains entrance to the 
hair follicles, where it produces inflammation and causes 
depilation. The inflammatory reaction causes a redness 
of the skin, hence the name. In a case of long standing 
the skin is red, thick, wrinkled, cracked, practically hair- 
less, and evolves a peculiar characteristic odor. The 
disease extends slowly upon the animal body, and it is 
not uncommon to find only one animal affected in spite 
of the fact that there are many swine in the same pen. 
Positive diagnosis can be made only by identifying the 
parasite microscopically. 

Treatment. — This condition is practically incurable, 
at least in so far as our present knowledge is concerned. 
Affected animals should be sent to slaughter, as this 



158 SWINE DISEASES 

condition does not impair the meat for food. If for any 
reason the animal is to be kept upon the premises, it 
should be placed in rigid quarantine. 

Tick Infestation 

Infestation of swine with ticks, particularly the ear 
ticks (Ornithodorus megnini), has attracted the attention 
of some southern swine breeders. These ticks locate in 
the external ear and produce irritation which annoys the 
infested animals. They may be removed by pouring 
into the ear some alcohol, dilute antiseptic or bland oil. 

Thread Worm Infestation 

Cutaneous infestation by Filaria iway occur in swine, 
but it has not been positively identified. 

Ringworm Infestation 

Rarely does ringworm occur in swine. The condition 
is caused by a Trichophyton. 

Lesions. — The lesions are usually located on the back 
or the outer surface of the thighs and are seen as isolated, 
circumscribed, round, red spots with a raised margin 
which bears small vesicles. The central portion appears 
normal, except that it is scaly. The trouble gradually 
extends in all directions, the raised vesicular margin 
representing the outside of the lesion. When the lesion 
becomes very large the center, or original lesion, has 
apparently recovered. The disease is transmitted by 
actual contact. 

Treatment. — Cleanse the affected parts and apply a 
five-percent solution of creolin, repeating the treatment 
on the fourth or fifth day. 



D 



SECTION VI 
CIRCULATORY ORGANS 

ISEASES of the circulatory organs may be of 
common occurrence in swine, but such dis- 
turbances are rarely recognized clinically. 



HEART 

Pericarditis 

Pericarditis, both acute and chronic, fibrinous and 
purulent, occurs in relation with hog cholera, swine plague, 
and erysipelas, and more rarely as a primary condition. 
The conditions luive been observed in autoi)sies. The 
acute type is characterized by hyperemia, hemorrhage, 
and exudation upon the serous lining of the pericardium. 
The serous surface of the pericardium will have lost its 
luster and the exudate may adhere to it in shreds. The 
pericardium becomes thickened in chronic })ericarditis, 
due to the formation of fibrous tissue. 

Hemorrhage 

Hemorrhages of small size are frequently found in 
the heart muscle. These occur in infectious diseases and 
are the result of bacterial emboli or injury of theca])illaries 
by chemic substances incidental to infection. They are 
of significance to the meat inspector and the diagnostician. 

Subendocardial hemorrhages are common as a sequel 
of infectious diseases. They are of diagnostic value and 
are an indication to the meat inspector of some infective 
disease or sej)tic intoxication. 

Fatty Changes 

Fatty changes in tlic heart muscle occur in i)ractically 
all swine that have been fattened for market. The fat 
particles are found between the muscle cells at first, but 

159 



160 SWINE DISEASES 

later the cells become infiltrated with fat. The heart is 
enlarged, is paler in color, and its density is diminished. 
No visible symptoms are evident, in the majority of these 
cases the swine being excessively fat and refusing to move 
about without urging. No treatment is required unless 
this condition arises in a breeding animal. 

Endocarditis 

Endocarditis has been observed by inspectors and in 
diagnostic autopsies, but the disease is not ordinarily 
recognized by the clinician. The lesions found usually 
consist of vegetative growths or denuded areas upon the 
endocardium, covering the valves. Either condition is 
always associated with infection, and it is not difficult to 
demonstrate bacteria in the lesions. 

Tumors 

Various tumors have been observed upon the peri- 
cardium and also in the myocardium. They are of no 
clinical significance, but are of interest to inspectors, 
as the presence of malignant tumors is considered suffi- 
cient evidence for condemnation. 

Parasites 

The pericardium rarely harbors the cystic form of the 
Taenia echinococcus, but Cysticerus cellulosse is of com- 
mon occurrence in the myocardium of swine. The lesion 
has the same general appearance as it does in voluntary 
striated muscle. Sarcosporidiosis is not uncommon in 
the heart muscle of swine. 

BLOOD VESSELS 

Diseases of the blood vessels of swine have received 
very little consideration, though a few cases of aneurism 
have been recorded. Thrombosis has been observed in a 
very few instances. Inflammatory disturbances have not 
been reported, or at least the available literature contains 
no records of such affections. Phlebitis has been observed 
by serum producers. This condition has occurred in the 



CIRCULATORY ORGANS 161 

ear veins, but has not been of sufficient importance to 
occasion any losses. 

BLOOD 

Diseases of the blood of swine have received very 
limited consideration up to the present time. 

Anemia 

Werner reported his observation of anemia in swine 
that had been fed watery slop food, while Braasch ob- 
served anemia in suckling pigs, but was not successful in 
identifying the cause. The usual lesions of anemia con- 
sist of lack of blood, paleness of the various tissues, 
emaciation, and a jelly-like consistency of the fat. The 
affected animals are depressed, weak, and gradually 
become emaciated. Later edematous swellings occur in 
the dependent parts of the body. 

Leukemia 

A few cases of leukemia have been observed in swine 
on postmortem examination. The exact cause of disease 
is unknown, but it is probably of an infectious origin. 

Lesions. — Porcine leukemic cases thus far observed 
are of the lymphatic type. The lymph glands become 
enlarged, due to hyperplasia of the lymphoid tissue, and 
there are frequently necrotic centers. By scraping the 
cut surface of a lymph gland a milk-white fluid is ob« 
tained. The spleen contains leukemic centers and is 
enlarged, and the liver may be similarly affected. 

Cases of leukemia have not been studied clinically. 
The disease is chronic in nature. 

SPLEEN 

The spleen is subject to hemorrhages and is engorged 
in hog cholera and in other septicemic diseases. 

Necrosis 

Necrosis of the spleen is of common occurrence m 
swine that have died as a result of injection of a virus 
containing the Bacillus necrophorus. These centers vary 



162 SWINE DISEASES 

in size from that of a dime to a fifty-cent piece, are grayish - 
white in color, and usually have a raised border and de- 
pressed center. There may be only one or two of these 
necrotic foci, or the spleen may be full of them. 

Hypertrophy 

Hypertrophy of the spleen is rather common. The 
condition occurs in leukemia, tumor formation, and in 
swine that are fed excessively. 

Tumors 

Sarcomatosis is a relatively common condition in the 
spleen. The^najority of the cases observed were primary, 
but secondary splenic sarcomas do occur. The tumor is 
usually multiple, the foci varying in size from mere points 
up to masses as large as a hen's egg. The centers are 
white or grayish-white in color, and are rather firm. 
They are usually circumscribed with a thin, fibrous 
capsule. 



SECTION VII 
THE NERVOUS SYSTEM 

DISEASES of the nervous system of the various 
domesticated animals have not been sufficiently 
investigated for a good description to be given 
of them. This is particularly true in regard to diseases 
of the nervous system in swine. 

Malformations of the brain or spinal cord are com- 
mon in swine. They are observed principally by the 
breeder and in small pigs, as the majority of these mal- 
formations are of such a nature that the affected animal 
dies soon after birth. Cranial and spinal clefts, with 
associated hernia of the meninges, brain, or spinal cord, 
are the most common deformities. 

Functional disturbances of the brain, such as deUrium, 
are sometimes observed, but this condition is not com- 
mon. It is usually the result of organic disease of the 
brain, although it may be caused by intestinal parasites. 
The affected swine champ their jaws, grunt, run against 
the fence, posts, or similar objects, tremble, and may even 
bite. When the cause is removed the animals make a 
speedy recovery, although succeeding attacks may occur. 

Viciousness is closely associated with dehrium. This 
condition is dependent upon the nature and tempera- 
ment of the animal and is manifested by a desire to attack 
man or other animals. Vicious swine bite, and boars use 
their tusks to inflict injuries, and are sometimes successful 
in disemboweling their victim. Viciousness is inherited 
or acquired, and vicious swine should never be used for 
breeding purposes. Viciousness is acquired by swine 
that are nervous. Such swine soon become irritable, 
then vicious, as a result of teasing or brutal treatment. 
One instance is recalled of a nervous sow that became 
vicious because the owner's son irritated and tantalized 

163 



164 SWINE DISEASES 

her by catching her small pigs and, while they were 
squealing, carried them around the pen. The best 
method to pursue in cases of viciousness in swine is to 
prepare them for slaughter and market them as soon as 
possible. 

Sunstroke and Heat Stroke 

It may be possible to differentiate between sunstroke 
and heatstroke in man, and possibly also in horses, but 
such a distinction is scarcely warranted in swine. 

Sunstroke is claimed to be due to the action upon the 
nerve cells of actinic rays of the sun, and heat stroke to 
a disturbed equilibrium of heat production and heat dis- 
sipation. The two conditions frequently occur simul- 
taneously in the same animal. 

Etiology. — These conditions are the result of direct 
exposure to sunshine and excessive heat. Driving swine 
in droves is occasionally accompanied by cases of heat 
stroke, and this may also be observed in carload lots in 
which the swine are crowded and the shipment made in 
extremely hot weather. The same condition arises in 
swine that are hauled in wagons, if proper precautions 
are not taken. Lack of proper shade predisposes the 
swine to sunstroke and to heat stroke. 

Lesions. — There are no gross lesions that characterize 
either sunstroke or heatstroke, except a parboiled appear- 
ance of parenchymatous tissues. Microscopically, the 
nerve cells are found to contain coagula, and there may 
be cloudy swelling of all parenchymatous tissues. 

Symptoms. — Uncertain gait, dullness, depression, 
increased respiration, and anxious expression are the 
principal symptoms observed in the early stages of these 
conditions. The temperature may be very high. Muscu- 
lar tremors, falling to the ground, and convulsions are the 
final symptoms. The course of the disease is short. 
In some instances the animal succumbs within a few 
minutes after the onset; in other cases the animal may 
Jive for from one to three days, and in rare instances 
may recover. 



THE NERVOUS SYSTEM 165 

Treatment. — Place the animal in a shady spot, 
give rapidly diffusable stimulants, and apply cool but not 
cold v\"ater over the body, and, if possible, use ice packs 
on the head. 

Lightning Stroke 

Lightning stroke sometimes occurs in swine, par- 
ticularly among those in pasture. The lesions of light- 
ning stroke are not well marked. Burning of the surface 
and irregular congested streaks may be observed. Tissue 
hemorrhage may or may not occur. The carcass of an 
animal dead from lightning stroke putrefies rapidly. 

Swine that are struck by lightning may be instantly 
killed or they may be rendered unconscious or only tem- 
porarily stunned. Those that are not killed will show 
unsteadiness of gait, and they may even be unable to 
walk. The animals that are not killed instantly usually 
make a speedy and complete recovery. Little is required 
in the way of treatment. The affected animals should 
be made comfortable and, if necessary, stimulants should 
be given. 

Epilepsy 

Epilepsy is a nervous disorder characterized by 
sudden temporary loss of consciousness, with partial or 
general convulsions. Swine, particularly those closely 
confined, are frequently affected with epilepsy. This is 
a functional disorder, the result of a variety of causes, 
parasites, tumorous growths, excitement, and fear being 
among the common causative factors, although in many 
cases the cause has not been determined. 

Lesions. — The disease is primarily a functional dis- 
order, and there are no lesions that are constant and can 
be said to be accountable for the seizures of epileps3^ 

Symptoms. — The approach of an attack is evidenced 
by restlessness, uneasiness, muscular tremors, rolling of 
the eyes, and champing of the teeth. These premoni- 
tory symptoms are succeeded by falling, and extension, 
and frequent jerking of the legs and head. The mouth is 
usually open, and from it saliva is discharged freely. 



166 SWINE DISEASES 

There may also be defecation, urination, and discharge 
of semen. The seizures are of short duration, rarely 
exceeding five minutes. The attacks may occur in rapid 
succession, or considerable time may elapse between 
attacks. 

Treatment. — Treatment is of no practical value, 
except to remove the cause when known. The affected 
animals should be destroyed if the seizures are frequent 
and severe, or in mild cases the animals should be pre- 
pared for market. They should never be used for breed- 
ing, as apparently the condition is inherited. 

Dentition Eclampsia 

A condition called dentition eclampsia occurs in young 
pigs. This is very similar to epilepsy. It is caused by 
the irritation resulting from the eruption of teeth, and 
future attacks are easily obviated by lancing the gums. 

Chorea 

Chorea is a neurotic condition characterized by rapid 
contractions of muscles or groups of muscles. 

Etiology. — In many instances chorea appears to be 
purely functional . Some have attributed it to Thrombosis ; 
toxic substances may be a factor; in producing it and in 
some cases malnutrition predisposes and possibly excites 
the condition. 

No constant tissue change has been identified with 
chorea. 

Symptoms. — Twitching of muscles or groups of 
muscles more or less continuously except during sleep 
characterizes chorea. The disease may be outgrown in 
the course of cne or two months, or it may become 
chronic. 

Treatment. — Various drugs have been recommended 
to relieve this condition, but the best plan is to destroy 
pigs that have aggravated cases, and to fatten and market 
those having mild attacks. 



THE NERVOUS SYSTEM 167 

Cerebral Hyperemia 

Hyperemia no doubt occurs in the brain and meninges 
of swine, but such cases have received meager cHnical 
investigation. A few cases of purulent cerebritis, or 
staggers, have been observed. Some of these cases were 
caused by wormeaten, moldy corn, or at least no new 
cases appeared after changing the feed. The cerebral 
tissue was affected and the lesion consisted of a liquefying 
necrosis, the necrotic area usually occurring in relation 
to the lateral ventricle and being unilateral in the cases 
investigated. The liquefied necrotic tissue was grayish 
red in color and usually represented an area about the 
size of an English walnut. The affected swine were 
generally dull in the beginning, but in one case observed 
the animal was excitable and delirious. Swine affected 
with cerebral hyperemia usually evidence an unsteady 
gait and may fall to the ground and show symptoms of 
convulsions. One case was observed that turned in a 
circle, jumped up from the ground, and performed other 
antics. 

Treatment. — Treatment is of little value after the 
brain substance has become necrotic. In the very early 
stages drastic purgatives may be of value, particularly if 
the cause lay in the provender. 

Parasites 

Rarely does the Cysticercus cellulosse develop in the 
brain of swine. The cyst does not develop as readily in 
the brain as in a muscle, and it is the exception to find 
a matured cyst in the nervous tissue. The symptoms 
produced will depend upon the location of the cyst in the 
brain. 



SECTION VIII 

INFECTIOUS DISEASES 

HOG CHOLERA 

HOG cholera is a specific septicemic disease of 
swine. It is contagious and infectious, and may 
be either acute or chronic. The disease is 
characterized by tissue hemorrhages and compHcations 
of the intestinal mucosa and, less frequently, by hemor- 
rhages of the lungs. 

Geographical distribution. — ^The first identified 
outbreak of hog cholera in the United States occurred in 
Ohio in 1833. From this original center it has spread 
widely and now prevails more or less continuously in 
every state of the Union as well as in the surrounding 
countries, including the island possessions of the United 
States. The disease was positively recognized in England 
in 1826, and it still prevails there. In 1896 approximately 
one third of the swine population of England died of 
cholera. The disease was introduced into Denmark in 
1887, and spread into Sweden the same year. It also 
appeared in France in 1887. Hog cholera, or a very 
similar disease, appeared in Germany in 1866, Prussia, 
Austria, and Hungary were invaded in 1895. From all 
reports, it is apparent that hog cholera prevails in prac- 
tically every country in which swine are maintained. 

Hog cholera was first investigated systematically in 
America in 1885, under the directions of Salmon. The 
disease was thought, and apparently proved at that time, 
to be due to a short, rod-shaped bacteria. 

De Schweinitz and Dorset further investigated the 
disease in 1903, and the Bureau of iVnimal Industry have 
continued their investigations up to the present time. 

Extent. — Information obtained from various sources 
indicates that hog cholera has been prevalent in America 

169 



170 SWINE DISEASES 

for the past thirty or forty years. The average annual 
loss in the United States for the past four decades prob- 
ably exceeds $50,000,000 annually, and in 1897 the losses 
due to this disease alone approximated $100,000,000. 
During the years 1912-13 a severe epizootic of hog 
cholera extended throughout the principal hog-raising 
section of the United States, the loss being excessive and 
for the country at large amounting to over $100,000,000 
each year. In 1913 there were 61,178,000 swine in the 
United States, of which ten to fifteen percent died of 
cholera. The losses from hog cholera in 1912 in Iowa, 
Nebraska, Kansas, and Missouri exceeded 3,000,000 
hogs valued at $30,000,000. The losses in Iowa alone for 
the years 1911-14 have exceeded $10,000,000 annually. 

Hog cholera is no doubt the most surely fatal disease 
of swine in America, and at this time it is the most im- 
portant disease economically in the United States. 

Etiology. — The cause of hog cholera is attributed to 
a filterable virus. The relation of a filterable virus to 
hog cholera was first recognized by De Schweinitz and 
Dorset in 1904, and similar investigations by Boxymeyer 
of Michigan were also concluded in 1904. Other inves- 
tigators have verified the findings by De Schweinitz and 
Dorset. The virus of hog cholera occurs in the blood and 
therefore in practically all the tissues of the body of an 
infected swine. One to two cubic centimeters of filtered 
blood serum from swine affected with hog cholera will 
produce typical symptoms of this disease when injected 
subcutaneously, intramuscularly, intraperitoneally, or 
intravenously into a healthy, susceptible pig. The 
symptoms become evident in from five to seven days after 
the inoculation. 

The virus has not yet been successfully cultivated, but 
very recent discoveries indicate that in the near future 
the cultivation of it may become practicable in the pro- 
duction of virus for the purpose of hyperimmunization of 
swine for the production of anti-hog-cholera serum. 

Hog-cholera virus is ultramicroscopic and passes 
through porcelain filters. ' The virus retains its virulence 



INFECTIOUS DISEASES 171 

in fluids at room temperature for from two to three 
months, but is destroyed by heating to seventy degrees 
Centigrade for one hour. When dried it becomes more 
resistant to the influence of high temperature. At the 
temperature of an ice box the virulence of the virus is 
retained for many months. It is very resistant to dilute 
solutions of phenol, corrosive sublimate, and chinosol. 
The length of time that virus may remain virulent on 
infected premises has not yet been determined, but it 
easily survives a single winter. 

In addition to the filterable virus, certain bacteria, 
including one Spirillum, may be factors in the causation 
of hog cholera. 

The Bacillus suipestifer is no doubt a factor in the 
production of secondary lesions and of some of the compli- 
cations of hog cholera, and from the original investigations 
under the direction of Salmon and some recent experiments 
it seems probable that an occasional outbreak of a disease 
very similar symptomatically and anatomically to cholera 
is caused by the Bacillus suipestifer. In fact, the intra- 
venous injections of the Bacillus suipestifer that have been 
recently isolated produce a septicemic disease that termi- 
nates fatally in from one to three days. It has been 
suggested that the disease produced by the Bacillus 
suipestifer be designated para-cholera. 

The Bacillus suipestifer is a short, motile, rod-shaped 
bacteria. It forms no spores, or at least none have been 
demonstrated. This organism grows aerobically and 
anaerobically on practically all artificial media. It will 
withstand ordinary dessiccation for four months or even 
longer, but sunlight destroys it when exposed only a few 
minutes. This organism produces an acute or chronic 
inflammation, and necrosis of the intestinal mucosa and 
the mesenteric lymph glands. If the animals are previ- 
ously starved and the acid reaction of the gastric juice 
neutralized before feeding the cultures of Bacillus suipes- 
tifer, they will contract an acute disease, with symptoms 
similar to those of septicemia, and usually die on the 
third day. Intravenous injections of the cultures pro- 



172 SWINE DISEASES 

duce septicemia, resulting in death in from one to three 
days. The infection with suipestifer is not transmissible 
from swine to swine, and swine that have recovered from 
the effects of infection with the Bacillus suipestifer are 
still susceptible to the filterable virus. 

Bacillus suisepticus is frequently demonstrable in the 
carcasses of swine that have died of hog cholera. This 
organism is the causative agent of swine plague, and will 
receive proper consideration in the discussion of that 
disease. Suffice to say at this place, it is frequently an 
associated infection with the filterable virus, the disease 
resulting being a mixed infection of hog cholera and swine 
plague. 

Spirochseta suis has been investigated by King and 
Hoffmann. The following are the conclusions of a report 
on it: "Its Significance as a Pathogenic Organism," that 
was published in Vol. 13, No. 12, of the Journal of Infec- 
tious Diseases: 

"Spirochseta suis is an organism found in the intestinal ulcers, 
crypts in the ceca, and external local lesions of animals suffering from 
hog cholera. It is a typical spirochete, simulating in many characteristics 
Spirochseta pallida, Spirochseta gallinarum, and other forms whose 
morphology and life history are becoming better understood. Spiroch- 
seta suis appears to be capable of breaking up into granules, and these 
granules may play an important part in the life cycle and physiological 
functions of the organism. They are present in the blood of cholera 
hogs, in cultures of the Spirochseta suis, and are capable of producing 
the disease in healthy hogs. 

"In the blood of hogs suffering from cholera the presence of a rela- 
tively large spirochete in a few numbers has been recognized. As 
this organism has not been found in the blood of normal hogs it may 
represent Spirochseta suis in a transitional form. Its morphological 
variation from Spirochseta suis, as found in ulcers and local foci, may 
be due to the unfavorable action of blood as a medium or to its natural 
processes as a part of the life cycle of the species. 

"Spirochseta suis is an obligatory anaerobic organism and usually 
requires several weeks' incubation for growth to take place on artificial 
culture medium. It may be transferred from generation to generation 
on artificial culture medium. Cultures containing the organism in 
the form of granules and spirochetes may be passed through bacteria- 
proof filters and the spirochetes removed, the few small granules which 
pass through being capable of producing hog cholera or resistance to 
the disease. 

"Spirochseta suis is capable of producing typical hog cholera when 
injected into healthy hogs. This is true not alone of contaminated 
cultures made directly from the intestinal ulcers of cholera hogs; second 
and third generations on artificial culture media, containing the Spiro- 



INFECTIOUS DISEASES 173 

ch«ta suis, as well as the Berkefeld filtrates of the same transfers, are 
capable of producing hog cholera and marked reactions, which confer 
more or less protection against the disease. The pathogenicity of these 
cultures does not appear to be due to the passage of an unknown 'invisible 
microorganism' which is finally transmitted to healthy hogs by inocu- 
lation. Control experiments tend to show that the pathogenicity of 
the cultures of Spirochaeta suis is due to the species itself in the form of 
spirochetes or granules. 

"Finally, in those hogs which receive the disease from cultures of 
Spirochseta suis, the organism is present in the intestinal lesions or 
local external lesions, as demonstrated by the dark-field examination. 

"From the above results, which have practically fulfilled Koch's 
laws, in so far as it is possible with an organism possessing the biological 
characteristics of spirochetes, it may logically be concluded that Spiro- 
chseta suis is more nearly established as the specific cause of hog cholera 
than any other known organism." 

From the foregoing it will be noted that there is still 
some contention as to the cause of hog cholera. At this 
time the filterable virus is usually given as the cause, but 
future investigations may reveal faulty technic or errone- 
ous conclusions of the experiments that have been con- 
ducted and estabhsh a new causative factor of hog 
cholera. 

Source of Infection. — The original source of the 
virus of hog cholera, like the origin of other viruses and 
pathogenic agents, is unknown. The following are the 
principal sources of virus of hog cholera: infected swine, 
the discharges from infected swine, the carcasses of swine 
dead of cholera, virus used in simultaneous immunization; 
food, water, vehicles of transportation, stock yards, and 
any other substance or objects contaminated with the 
discharges of infected swine, or the tissue juices or prod- 
ucts of the carcasses of swine dead of cholera. 

From the foregoing the ease of obtaining infection is 
readily comprehended. The virus is transmitted from an 
infected swine on noninfected premises to other swine, or 
to soil, food, water, bedding, and general surroundings, 
thus practically insuring infection of other swine on the 
same premises and other premises as well. Serious out- 
breaks of cholera are sometimes traceable to the intro- 
duction of a new boar, or other animal, that is infected. 

If the carcass of a swine dead of cholera is permitted 
to remain in the hog lot, other swine will become infected 



174 SWINE DISEASES 

by eating of the flesh, and the soil and surroundings will 
be contaminated with the virus. Some men have shown 
their faith in the protection of swine against cholera with 
serum by putting the carcass of a swine dead of cholera in 
their pens and thus infecting their premises. 

From the lack of care in the use of virus in producing 
a permanent immunity there is little doubt but that hun- 
dreds of farms have become infected. Food hauled in 
wagons or other vehicles that have been previously used 
in transporting cholera-infected swine may become 
contaminated and infect healthy, susceptible swine and 
thus produce hog cholera. Water, too, is frequently the 
source of "infection. This is especially noticeable in the 
spread of hog cholera in sections of country in which there 
are many small streams. Such enzootics usually follow 
the streams. The contamination of surface water is due 
to the discharges, and even to the carcasses of cholera- 
infected hogs being washed by rain water into the small 
streams. Many hog raisers have fenced and made 
pastures of the low lands and the small streams of water, 
thus favoring the introduction of infection into their 
herds. 

Almost every state in the Union, and many foreign 
countries, permit the shipment of cholera-infected swine to 
market centers. By this means stock yards, stock cars, 
and the railroad right of way become contaminated with 
the discharges of cholera-infected swine, and the chances 
are that some of the discharges contain the virus of hog 
cholera in a sufficiently virulent form to produce cholera 
in healthy, susceptible swine. By this means cholera is, 
no doubt, frequently transported hundreds of miles, and 
new centers produced. As yet few if any states actually 
require the cleaning and disinfecting of cars that are 
known to have been used to transport cholera-infected 
hogs to market, and therefore the cars continue as a 
source of infection for some time after the cholera- 
infected hogs have been unloaded. By the practice of 
shipping cholera hogs to market, practically all public 
stock yards become infected and are therefore a source of 



INFECTIOUS DISEASES 175 

danger in the community. The cholera-infected swine 
are hauled or driven from the farm to the railroad station 
along or over the public road, which thus becomes a 
source of infection, the virus of w^hich may collect on the 
feet of horses, on the wheels of wagons or other vehicles, 
and be transported to farms where infection had not 
before been present. 

The possibility of virus carriers of hog-cholera infec- 
tion must be admitted, for such carriers and distributers of 
infection are recognized in other infective diseases. It 
has been claimed by good authorities that swine immun- 
ized simultaneously do not eliminate the virus, but this 
claim has not been satisfactorily proved, and because of 
the possibility of such swine eliminating infection, they 
must be considered a source of infection. 

Dogs, crows, buzzards, and pigeons are scavengers, and 
are an important factor in the dissemination of infection. 
Neighbors visiting back and forth and exchanging labor 
are prolific means of carrying infection from place to 
place. And careless veterinarians have in some instances 
apparently been responsible for the transmission of hog 
cholera from infected to non -infected premises. 

Manner of infection. — Hog cholera may be trans- 
mitted by direct or indirect infection. Direct infection 
may be affected by the actual contact of a healthy, 
susceptible swine with one affected with cholera. Direct 
infection may also occur in utero, the pigs becoming 
infected before birth. This statement may be questioned 
by some, but the fact that pregnant sows abort when they 
become affected with hog cholera is common knowledge 
among swine breeders. It has also been observed that 
abortion is of frequent occurrence in pregnant sows that 
are simultaneously immunized. The transmission of the 
virus from the sow to the pig in utero would not seem 
difficult when it is remembered that this virus readily 
passes through porcelain filters. 

Indirect infection also is of common occurrence in 
hog cholera. This is accomplished by the infection being 
introduced on food stuff, in water, in the inspired air, or 



176 SWINE DISEASES 

on foreign bodies, such as splinters or stubble. Indirect 
infection is the manner of infection that occurs when new 
centers are established without the introduction of a 
diseased animal. 

Susceptibility. — Young swine are apparently most 
susceptible to cholera immediately after w^eaning. How- 
ever, swine of all ages may become affected. Thus 
sucking pigs or old brood sows or boars may contract 
cholera and die of its effects. 

Channels of entrance of the infection. — ^The virus 
of hog cholera most frequently gains entrance to the body 
of the swine by way of the digestive tube, upon contami- 
nated food or water, or in various substances that swine 
are likely to chew or ingest. Infection may also be 
introduced through the respiratory tract, but infection 
by this avenue of entrance is not common. The virus 
may be introduced through the skin by means of barbs, 
awns, splinters, or similar objects, but this avenue of 
entrance is not common in natural infection. 

In the production of a permanent immunity by the 
use of the virus and serum, the virus is introduced through 
the skin by a hypodermic syringe. Injection for the 
purpose of hyperimmunizing, in the production of anti- 
hog-cholera serum, is done intravenously in an ear vein. 
Infection can be successfully accomplished by intraperi- 
toneal or intramuscular injections of the virus, but natu- 
ral infection rarely occurs in this way. 

Period of incubation. — The period of incubation 
after natural infection is variable, depending upon the 
virulency of the virus and the resistance of the infected 
swine. In most instances there will be a rise of tem- 
perature from the fifth to the seventh day, and the 
animals will be visibly sick by the tenth day after infec- 
tion. The period of incubation in inoculation experi- 
ments varies from four to seven days. 

Lesions. — The anatomical changes observed in hog 
cholera are quite variable because of the multiform types 
that it assumes, probably due to complications. The 
following types have been described: pure hog cholera 



INFECTIOUS DISEASES 



177 



or septicemic form, intestinal form, pectoral form» and 
mixed form. The first-named is uncomplicated hog 
cholera; the other forms are due to compHcations. 

Septicemic form. — In the very acute cases no gross 
lesions are evident except cloudy swelling of the paren- 
chymatous organs indicating a high antemortem tem- 
perature. In the ordinary acute cases the lesions corre- 
spond to those of septicemia and consist of hemorrhages 





A B 

Fig. 11.— MUCOUS ME»IBBANE OF THE BLADDER. 
A. Normal. B. showing inflammation due to hog cholera. 

in the serous membranes, in the mucous membrane of the 
epiglottis, trachea, lung, pharynx, and usually in the 
spleen and kidneys. The lymph glands are hyperemic 
and the lung usually contains small areas of croupous 
pneumonia in the cardiac lobe. The skin may be hy- 
peremic, and there may be subcutaneous hemorrhages. 
The bone marrow is usually dark red or black. 

Intestinal form. — This type is apparently a complica- 
tion due to the simultaneous activity of the filterable 
virus and the Bacillus suipestifer, Bacillus necrophorous. 



178 SWINE DISEASES 

Bacillus coli communis, Spirochseta suis, or some other 
intestinal infection. This type of hog cholera is charac- 
terized by the general lesions of the less acute septicemic 
type plus intestinal lesions which are as follows. The 
lymphoid tissue of the mucosa of the cecum, colon, and 
to a less extent in the ileum, becomes tumefied and later 
undergoes necrosis. The necrotic tissue, remaining ad- 
herent as a dirty brown mass, has raised margins and 
represents the so-called hog-cholera ulcer. These necrotic 
areas may be mere points or they may be as large as a 
silver dollar or even larger. In exceptional cases the 
necrosis may extend through the intestinal wall and 
result in fatal peritonitis or intestinal adhesions. In the 
chronic intestinal type there is intestinal adhesions, in- 
volving especially the large intestine, although the small 
intestines may also evidence the same lesions. There 
may be a general diffuse diphtheritic inflammation of the 
mucosa of the intestine and stomach, the exudate cover- 
ing practically the entire surface of the mucous membrane 
of the intestine. This organized exudate may become 
dry or it may become softened and mushlike, the color 
of the exudate changing from dirty brown to a yellow or 
greenish yellow. 

In chronic cases the septicemic lesions become modi- 
fied. The hemorrhages become pigmented areas; the 
lymph nodules become hyperplastic and frequently necro- 
tic. The spleen may or may not become extensively 
enlarged and necrotic, the skin frequently becomes necro- 
tic and variable sized areas slough, and the ears become 
tumefied and frequently necrotic, and slough. Tume- 
faction and necrosis may also occur in the bladder, mouth, 
pharynx, and in other regions. 

The evidence of a previous attack of this type of hog 
cholera consists of granulation of the erosions of the 
mucous membrane of the intestine, stomach, mouth, and 
elsewhere, and also of granulations of the skin erosions. 
In other cases there may be scars and an irregular lumen 
of the intestine due to irregular cicatrization. The lymph 
nodes will contain caseous necrotic centers. 



INFECTIOUS DISEASES 



179 



Pectoral form. — This type consists of the hemorrhagic 
form in varying degrees of intensity and pulmonary 
lesions which may or may not be associated with pleurisy. 
As previously stated, croupous pneumonia commonly 
occurs in the septicemic form, but it is more extensive in 
the pectoral form. 




Fig. 13.— MUCOLS MEMBRANE OF THE INTESTINE. 

A. Normal. B. showintf effect of chronic inflamination due to hog 
cholera. C. typical hog cholera ulcers. 



The usual pulmonary lesion consists of croupous pneu- 
monia involving especially the cardiac lobe of the lung. 
The appearance of the lung will depend upon the stage of 
pneumonia existing at the time of death of the animal. 
The affected portion may be in the congestive, red, or 
gray hepatization or resolution stage, and occasionally 
there may be abscess formation or necrosis. More 



180 SWINE DISEASES 

rarely will there be evidence of catarrhal pneumonia, 
except in those cases of the simultaneous occurrence of 
hog cholera and swine plague. The lesions of simple 
catarrhal pneumonia occur in the lower portions of the 
lung, and are the same when it occurs as a complication 
of hog cholera as in the primary affection of catarrhal 
pneumonia which has been previously described (p. 88). 

Pleurisy may accompany the pneumonic form of hog 
cholera, but it is exceptional to observe such cases. The 
pleurisy may be serous, fibrinous, or hemorrhagic, and 
in exceptional cases it may become purulent or septic. 

Although subepicardial and subendocardial hemor- 
rhages are typical of the pure, uncomplicated hog cholera, 
these lesions are more extensive in the pectoral form of 
the disease. 

Mixed form. — The mixed form of hog cholera consists 
of the septicemic form plus comphcations of the intestinal 
and pectoral forms. This form of hog cholera is prob- 
ably more prevalent than any other type described, and 
this fact accounts for the difficulty that is frequently 
encountered in making a diagnosis. 

All of the different forms of hog cholera described are 
frequently found in one herd of hogs. Occasionally pecu- 
liar combinations of lesions are observed, and in some 
instances it is not possible to make a diagnosis until 
several autopsies have been performed. In one instance 
four hogs were autopsied and hemorrhagic gastritis was 
the only lesion found. Two days later another hog was 
autopsied, and revealed typical lesions of hog cholera. 

Symptoms. — Symptoms of hog-cholera are as varia- 
ble as the lesions. For convenience in describing the 
symptoms will be considered in four groups corresponding 
to the four types mentioned in the consideration of 
lesions. 

Septicemic form. — The most acute or so-called peracute 
cases are frequently found dead, having evidenced no 
symptoms. The ordinary acute cases evidence the fol- 
lowing symptoms, usually in the order mentioned. The 
affected animals are inclined to isolate themselves and 



INFECTIOUS DISEASES 



181 



stand with back arched and head hanging, or they may 
crawl under the bedding. The appetite is at first im- 
paired, later the animals refuse all food. In the early 
stages vomiting may be observed. There is usually con- 
stipation in the beginning, but this is succeeded by 






Fig. 13.— HEARTS. 

A. Showing- acute iiiflanimation of the auricle and hyperemic areas 
in the ventrical, a common condition in liog cholera. B. normal. 



diarrhea, the intestinal discharges being admixed with 
blood. There is usually a purulent conjunctivitis; the 
discharges accumulate on the eyelashes and frequently 
cause adhesion of the eyelids. There may be a limited 
mucopurulent discharge from the nose. On the second 
or third day erythema of the skin usually becomes evi- 



182 SWINE DISEASES 

dent, the discolored areas being observed on the venter 
surface inside the thighs, and are red or reddish purple in 
color. The ears become tumefied due to congestion and 
edema. There is a rise of temperature, the high tem- 
perature ranging from 105 to 107 degrees Fahrenheit, or 
even higher, persisting throughout the acute attack. 
The affected animals become weak as the disease pro- 
gresses, and it usually terminates fatally in from two to 
seven days. In some instances the first manifestation of 
the disease consists of rheumatoid symptoms, the disease 
sometimes being diagnosed as rheumatism. 

Intestinal form. — The intestinal form of hog cholera 
is manifested by symptoms similar to those described in 
the septicemic form but less intense. This form of the 
disease is less acute and runs a longer course. Symptoms 
of digestive derangements are the principal evidence of 
the disease and consist of impaired appetite, inappetence, 
vomition, constipation alternated with diarrhea, weak- 
ness, and rapid emaciation. Purulent conjunctivitis is 
usually present. A bad odor emanates from the mouth 
and on inspection putrefying accumulated inflammatory 
exudate is observed adhering to the buccal mucous mem- 
brane. The tonsils and pharyngeal mucous membrane 
may be hyperemic and hemorrhagic. Erythema of the 
ventral surface may exist, the ears become tumefied, and 
occasionally necrosis succeeded by sloughing occurs. 
Areas of skin on the back or croup may become necrotic 
and slough, leaving large, deep, ugly wounds. 

The course of the disease varies from two to four 
weeks, the majority of the affected animals succumbing, 
but occasionally one or more recover after a long period 
of convalescence in which the diarrhea is gradually over- 
come. There is desire for food, and ultimately there is 
a normal appetite and the animal gradually becomes 
stronger and finally recovers. 

Pectoral form. — The symptoms of the pectoral form 
of hog cholera consist of the symptoms of the septicemic 
form of cholera and of pneumonia. The symptoms of the 
septicemic type are usually evident when the pneumonia 



PLATE I. 



Fig. 1 




r .-•'•^f "^"^.-^ -v** -' ' ^ urn. 



f ^I 



'» 



»i# 






■^ 




Fig. 2 



Fig. 1. Normal skin and skin showing red blotches 
characteristic of hog cholera. 

Fig. 2. Serous surface of intestine, showing sharply 
outlined petechial hemorrhages, due to hog cholera. 



INFECTIOUS DISEASES 



183 



begins. The affected animals show disturbance of respi- 
ration by coughing, dyspnea, and more or less nasal dis- 
charge, the intensity of the pneumonic symptoms depend- 
ing upon the extent of lung involved in the pneumonic 
process. The physical examination of the lung is prac- 
tically impossible because of the thick chest wall, and the 
respiratory sounds and solidity of the lung can be a matter 




Fig. 14.— HOG CHOLKRA, (Early Stage). 

of conjecture only with the clinician. Conjunctivitis is 
usually prominent in the pectoral form of cholera. Ery- 
thema, tumefaction, and necrosis of the ear and other skin 
surfaces are not so common in the pectoral as in the intesti- 
nal form of the disease. Some digestive derangements 
are always present, but they are less intensive than in 
the intestinal form. A high temperature prevails in the 
pectoral form, and as a rule it will average from one to 
two degrees Fahrenheit higher than in the intestinal form. 



184 SWINE DISEASES 

The course of the pectoral form of cholera varies from 
one to three weeks. The disease frequently terminates 
fatally within one week, especially when there is extensive 
lung involvement. A few cases may assume a chronic 
form and ultimately recover. 

Mixed form. — This is the usual form of cholera, and 
the symptoms evidenced will depend upon the complica- 
tions. There will be symptoms of digestive derange- 
ments, such as inappetence, vomition, constipation, and 
purgation; of pneumonia, such as cough, dyspnea, and 
nasal discharge; conjunctivitis and cutaneous erythema, 
tumefactions, and necrosis, the intensity of these various 
symptoms depending upon the proportionate involve- 
ment of the various groups of organs. In addition there 
will be more or less of the symptoms of the septicemic 
form of cholera, such as reluctance to move, depressed 
head, arched back, and high temperature. In the acute 
form of the mixed type of cholera the course is of brief 
duration, terminating fatally in from one to three days 
after the first symptoms become evident. ;j 

Diagnosis. — From the foregoing description of lesions 
and symptoms it is very evident that the diagnosis of 
cholera is rather difficult. There are some laymen, and an 
occasional veterinarian, who diagnose as hog cholera 
practically all diseased conditions of swine. Much has 
been written during the last few years concerning the diag- 
nosis and treatment of cholera, but the bulk of this lit- 
erature has come from serum producers, and some of it 
has apparently been written without sufficient investiga- 
tion to justify the conclusions. fi'^i 

The symptoms evidenced may cause a clinician to 
suspect cholera, but the diagnosis should not be based 
upon symptoms alone. Lesions observed in autopsy may 
or may not be sufficiently characteristic for one to arrive 
at a positive diagnosis of cholera. The intestinal lesions 
— that is, the tumefied lymphoid tissue, necrosis, and 
ulceration that occur so commonly in the intestinal form 
of cholera — may occur in the intestine of swine that are 
not infected with the filterable virus. Necrosis and ul- 



INFECTIOUS DISEASES 



185 



ceration have been observed as a result of infection with 
the Bacillus necrophorous, and these lesions have also 
been observed in swine that had been fed excessive quan- 
tities of ferrous and copper sulphate. 

The study of the lesions gives assistance in the diag- 
nosis of cholera. The pneumonic lesions are relatively 
common in cases of cholera excepting in the peracute 




Tig. 15.— ACUTE HOG CHOLERA, (Advanced Stage). 



type. The lesions in the lung consist of croupous pneu- 
monia in some stages and involve the cardiac and fre- 
quently the cephalic lobe. This lesion cannot be consid- 
ered characteristic of cholera as it is the typical lesion of 
croupous pneumonia, but when it occurs in conjunction 
with subserous and submucous hemorrhages, congestion 
and hemorrhages of lymph nodes, and discoloration of 



186 SWINE DISEASES 

bone marrow the evidence is in favor of the existence of 
cholera. 

Swine plague is distinguished from the pectoral form 
of cholera by the fact that the former is characterized by 
catarrhal pneumonia in the early stages of the disease, 
and by necrotic pneumonia in the later stages, and also 
by the presence of fibrinous pleurisy with or without 
adhesions. 

Petechial hemorrhages of the kidney were formerly 
considered pathognomonic of cholera, but these hemor- 
rhages have been found in the kidney rather frequently 
when cholera was absent, or at least the blood from such 
cases failed to produce cholera in healthy, susceptible 
pigs. 

Engorgement of the spleen is a common lesion in 
acute cholera, but this condition sometimes occurs as a 
result of disturbed digestion and as a result of leukemia, 
and is a common lesion of other septicemic diseases. 
Therefore enlarged spleen alone should not be considered 
a sufficient evidence upon which to base a diagnosis of 
cholera. 

The congestion and hemorrhage of the lymph nodes 
is one of the most common and characteristic lesions of 
cholera, but this lesion is not always present. Hemor- 
rhages of the subserosa and submucosa are quite constant 
in cholera; however, they may occur in any other septi- 
cemia. The changes of the bone marrow, although oc- 
curring to a less degree in other septic conditions, are 
among the most characteristic lesions of cholera, but this 
lesion is absent in some of the peracute cases. Petechial 
hemorrhages are also of common occurrence in swine 
erysipelas, but this disease can be differentiated from 
cholera by the demonstration of the organism of swine 
erysipelas in the blood or splenic pulp. 

The principal diagnostic lesions of cholera are sub- 
serous and submucous hemorrhages, congestion and 
hemorrhages of the lymph nodes, and the discoloration of 
the bone marrow. Next, in order of frequency, is croup- 
ous pneumonia of the cardiac lobe of the lung. 



INFECTIOUS DISEASES 



187 



In the diagnosis the history of the outbreak, and par- 
ticularly the distance from known cases of cholera and 
whether or not any swine have recently been introduced, 
must always be taken into consideration. Finally, it 




V \ 




Fig. 16— HEART SHOWING TISSUE HKMOKKHAGES DUE TO 

HOG CHOLEUA. 
B. Hyperemic areas. 



188 



SWINE DISEASES 



must be understood that the only absolute method for 
the diagnosis of cholera at this time is the inoculationTol 
a known, healthy, susceptible pig with from one to five 
cubic centimeters of blood from the suspected animal. 
Thus determine the presence or absence of cholera. 




B 



A. Normal. 



Fiff. 17.— KIDNEYS. 

B. hog- cholera (turkey egg) kidney. 



Prognosis. — The peracute septicemic form of cholera 
is nearly always fatal. An occasional animal may recover 
from the ordinarily acute septicemic type, but the large 
percentage so affected succumb. The pectoral form is 
usually quite fatal, in some localities fully ninety percent 
of the affected swine dying. The intestinal form is less 



INFECTIOUS DISEASES 



189 



fatal and has a tendency to become chronic, the course in 
such cases varying from one week 'to two or three months. 
Treatment.~It is probable that more proprietary 
remedies have been devised and advertised as hog-cholera 
cures than for any other disease of domesticated animals. 
The apphcation of therapeutic agents other than anti- 
hog-cholera serum has not proved satisfactory in any 
proved outbreak of cholera. 




Fig. 18.--T.YMFH NODES. 
A. Normal. B. hyperemic clue to hog cholera. 

With this disease, as with any other, prevention is 
far better than treatment of afflicted animals. It is a 
preventable disease, but unfortunately it has been re- 
sponsible for extensive losses of swine for so many years, 
in practically every country, that the swine breeders 
and swine raisers have apparently become accustomed to 
the losses and accept them as a matter of fact, and until 
recently with little concern as to methods of prevention. 
The prevention of hog cholera may be accomplished by 



190 SWINE DISEASES 

complying with the laws of hygiene, the enforcement of 
sanitary police regulations, and by immunization of swine 
by the use of anti-hog-cholera serum. 

The laws of hygiene of other domesticated animals 
than swine are fairly well provided for by the stock 
raisers. It has been the custom, and it is still far too com- 
mon at the present WTiting, to consider that anything is 
good enough for swine. Thus many men having exten- 
sive financial interests in pork production are constantly 
seeking fermented grain and moldy and otherwise spoiled 
or damaged foods for their swine because such food stuff 
can usually be purchased for less money than a clean, 
wholesome food. But such foods interfere with the diges- 
tion, thus weakening the animals and rendering them 
more susceptible to disease. Swine that are given the 
proper diet are not necessarily immune to cholera, but 
they are much more resistant than swine affected with 
digestive derangements. Swine should also receive an 
abundance of clean, wholesome water, and not be required 
to drink water from polluted streams or stagnant pools. 
Many cases of what would probably have been fatal cases 
of cholera have been nursed back to health by providing 
good surroundings and a diet of clean, sweet milk. 

Hog pens should not be placed, as they frequently are, 
in locations that cannot be drained properly. It 
is not necessary for swine to have mud and filth for their 
existence. They will thrive better when kept in sanitary 
quarters. 

Sanitary police regulations, or general sanitation in 
relation to control of hog cholera, have certainly not 
received proper consideration. If rules and regulations 
were instituted prohibiting the dissemination of hog 
cholera, the losses could be rapidly diminished. The 
following provisions for quarantine and shipping regula- 
tions were recommended by the committee on Uniform 
Methods for the Control of Hog Cholera at the meeting 
of the United States Live Stock Association in December, 
1913: 

1. The shipment or movement, interstate, of swine affected with 
cholera to be prohibited. 



INFECTIOUS DISEASES 191 

2. Exposed swine to be shipped under permit and placard. 

3. The movement of cholera-infected swine over the public high- 
ways to be prohibited. 

4. Provision for moving exposed swine under permit in approved 
manner. 

5. Carcasses of animals, and particularly of swine that have died 
of cholera, to be burned within twenty-four hours after death, or under 
special permit to be disposed of otherwise. 

6. The shipment by rail of swine for purposes other than immediate 
slaughter to be permitted only through special pens and unloading 
chutes, or through portable chutes directly into wagons. If unloaded 
in regular loading pens, to be moved under permit in approved manner. 

7. Public stock yards to be under close supervision and cleaned 
and disinfected at intervals determined by the proper state authorities. 

8. Railway cars for the transportation of swine other than such as 
are intended for immediate slaughter to be cleaned, washed, and dis- 
infected before swine are loaded. 

9. All cars in which diseased swine are found, or in which exposed 
swine were shipped for immediate slaughter, to be cleaned, washed, 
and disinfected within twenty-four hours after unloading, or cars to 
be held until the presence or absence of diseases has been determined. 

10. All cars or vehicles of transportation carrying cholera-exposed 
swine to be placarded in a conspicuous manner, "Cholera Exposed 
Swine for Immediate Slaughter." 

• 11. Owners of swine and persons in charge, , including attending 
veterinarians, to report without delay to state authorities all outbreaks 
of cholera among swine. 

12. Live-stock sanitary authorities to quarantine all infected herds 
and premises, but may permit shipment of exposed swine for immediate 
slaughter as above provided. 

13. Infected premises to be quarantined not less than sixty days 
after last traces of disease have disappeared and premises have been 
cleaned and disinfected. 

14. Infected premises to be cleaned and disinfected under super- 
vision prescribed by live-stock sanitary authorities. 

15. The live-stock sanitary authorities to be given power to provide 
in a practicable manner against the dangerous pollution of streams 
with hog-cholera virus and provide for the safe disposal of garbage 
liable to be infected with hog-cholera virus. 

16. To prevent the spread of hog cholera by swine shown for exhi- 
bition purposes, such swine to be treated with serum and virus not less 
than forty days prior to the opening date of the exhibit, or with serum 
alone not more than fifteen days before such time. 

17. Provision for controlling for thirty days, by quarantine or 
otherwise when deemed advisable by the proper authority, of all swine 
treated with serum-virus, or premises on which such swine are kept, 
to prevent danger of possible spread of infection from inoculated animals. 

If the above or similar regulations could be instituted 
and enforced there is no doubt that cholera in swine 
would be materially diminished and could be eradicated, 
ultimately, by the judicious use of serum, from this or 
any other country. Since thft advent of anti-hog- 



192 SWINE DISEASES 

cholera serum the enforcement of sanitary regulations 
has been neglected. In order to obtain and enforce 
efficient sanitary measures the pork producers must first 
be educated to the necessity of such measures. 

The application of some of the simple sanitary rules 
have proved of great monetary value to swine raisers. 
As an illustration, the separation of the infected from the 
healthy swine by means of a clinical thermometer, and 
the proper after-care, have been the means of saving over 
fifty percent of many infected herds. 

If more consideration were given to proper hygienic 
care and sanitary control, and less to the production, dis- 
tribution, and application of serum, it is possible that 
hog cholera would soon become a much less serious dis- 
ease economically. 

Preventive Treatment.— The first use of serum for 
the prevention of hog cholera was made in 1897 by 
Preisz, who obtained it from a swine that had recovered 
from cholera. In 1904 De Schweinitz and Dorset de- 
monstrated that hog cholera was caused by a filterable 
virus, and soon thereafter Dorset, McBryde, and Niles 
devised a plan of hyperimmunizing swine for the purpose 
of producing anti-hog-cholera serum. This serum came 
into general use about 1908, and is now being used ex- 
tensively in the United States. It is prepared on the 
following general plan, different manufacturers having 
slightly different methods. 

The production of serum is of considerable importance 
and a brief description of the general process follows : 

Swine having a large carcass and weighing 225 to 275 
pounds are selected, and if they are not known to be im- 
mune they are immunized by using twenty-five to thirty- 
five cubic centimeters of serum to the hundred pound hog 
weight, and from one to two cubic centimeter of virus. 
The swine used for hyperimmunes are tuberculin tested 
and reactors are discarded. After the swine has recovered 
from the immunizing process, which requires from ten 
to twenty days, it is then hyperimmunized. A pre- 
requisite of the hyperimmunizing process consists in 



INFECTIOUS DISEASES 193 

having all instruments, bottles, and so on, sterile, and of 
having environments that are conducive to asepsis. The 
immune swine that are to be hyperimmunized should be 
kept in a pasture or yards that are concreted to prevent 
undue filthiness. The virus used may be obtained from 
the field, that is, from natural outbreaks of cholera, or it 
may be produced by injecting healthy, susceptible pigs 
with one to two cubic centimeters of virus. A pig 
weighing from sixty ro ninety pounds is usually used. 
The virus pigs should be carefully observed, and tempera- 
ture records maintained. If susceptible pigs have been 
injected with a virulent virus there will be evidence of 
the disease in four to seven days, and from the seventh 
to the ninth day the temperature of the pig will probably 
range from 105 to 108 degrees Fahrenheit, and is thcD 
prepared for slaughter by thoroughly washing and apply- 
ing some disinfectant to the skin of the venter surface of 
the body. In addition to these precautions the inferior 
cervical region is shaved. The entire pig is shrouded with 
moist, antiseptic gauze to prevent any particles of dust 
from dropping into the vessels used in collecting the virus. 
The vessels are severed, and the blood is collected in a 
sterile vessel and the fibrin whipped and removed; the 
remainder of the blood is filtered through gauze, and con- 
stitutes the virus blood. The virus pig is then autopsied, 
and if lesions of cholera are not found, or if lesions of 
other diseases are found, the collected virus blood is 
discarded. The collection of field virus requires the same 
precaution. 

Hyperimmunizing may be accomplished by the intra- 
peritoneal, intravenous, or intramuscular injections of virus. 
The quantity of virus employed depends upon the method 
used, that is, the slow or quick method. For the intravenous 
and intramuscular methods five cubic centimeters of virus 
are used to the pound weight of the hog that is being hyper- 
immunized. This quantity is divided and given in two 
injections in the slow process and as a single injection in 
the quick process. In the intravenous method the 
injection is made in an ear vein after properly cleaning and 



194 



SWINE DISEASES 




Fig. 19.— VIRUS BLEEDING ROOM. 

1. Revolving door upon whicli the pigr is secured and cleaned. The 
door is then turned, which brings the pig into the bleeding room. 

2. shrouded pig. 



INFECTIOUS DISEASES 195 

securing the animal. Various devices are used in making 
the injection. The principle involved is to force the virus 
into the vein sbwly. The virus should be near the body 
temperature when injected. In the intra-muscular meth- 
od the virus is injected in the interstices between the 
muscle bundles, selecting two, three, or four locations, 
as the inner thigh muscles and the subscapular region. 
The intraperitoneal injection is made by passing a long 
needle through the abdominal parietes into the peri- 
toneal cavity. 

The hyperimmunes are kept in clean, sanitary pens 
and a temperature record maintained in order that the 
producer may know when the reaction is over. When 
the temperature assumes the normal the blood contains 
the antibodies. Two methods of bleeding hyperimmunes 
are in use — the slaughter method and tail bleeding. By 
the slaughter method practically all of the blood is ob- 
tained. By the tail-bleeding process from tw^o to four 
bleedings are made, and the sw ine are re-hyperimmunized, 
and after the reaction they are used for bleeding. Some- 
times the hyperimmune is tail bled for one, two, or three 
times and then slaughtered. Each method has some 
advantages and some disadvantages. The slaughter 
method is the most rapid — in other words, more serum 
can be produced in a given length of time than by tail 
bleeding. Tail bleeding is the most economical method 
of producing serum, and antiseptic precautions can be 
carried out more effectually. 

Proper equipment is required for either process, and 
the instruments, bottles, and other utensils used must be 
sterile and the environment must be conducive to asepsis. 

The blood obtained from hyperimmune swine is 
whipped, the fibrin being removed and the remaining 
portion of the blood filtered through gauze. When ob- 
tained by the slaughter method, the blood from each hog 
is kept separately until the carcass is autopsied and the 
absence of cholera and other diseases is demonstrated. 
The blood may also be kept in one container. Centrifu- 
gation of the blood is being practiced by some producers. 



196 



SWINE DISEASES 




Fig. 20.— HYPERIMMUNIZING R003I. 
1. Virus container showing attachment to pressure tank. 2. needle 
inserted into the ear vein. 



' INFECTIOUS DISEASES 197 

and this should be encouraged, as a cleaner product and 
one that is more easily injected is produced. The blood 
obtained from hyperimmune swine by either process is 
preserved by adding a small percentage of phenol or 
trikresol and properly sealed and placed in storage at a 
temperature of about 50 degrees Fahrenheit. Before the 
serum is used it is tested. First, second, third, and fourth 
bleedings from different hyperimmunes, or the blood from 
different hyperimmunes obtained by slaughtering, are 
mixed up to quantities of 80,000 cubic centimeters. This 
amount constitutes a series, and therefore each series is 
a composite serum. For a test sample a proportionate 
quantity is taken from each separate quantity that makes 
up a series. The sample should be obtained immediately 
after bleeding, thus obviating reopening of the bottles. 

For the test eight healthy, susceptible pigs, weighing 
from sixty to ninety pounds each, are selected. These 
pigs are maintained in four separate pens of two each. 
The test is made as follows: Each of the eight pigs is 
injected with two cubic centimeters of virus; pigs No. 1 
and No. 2 receive twenty-five cubic centimeters of serum; 
pigs Nos. 3 and 4 receive twenty cubic centimeters of 
serum; pigs No. 5 and 6 receive fifteen cubic centimeters 
of serum; and pigs Nos. 7 and 8 receive the virus only. 
Pigs Nos. 7 and 8 are designated check pigs, and they 
should show visible symptoms and die of typical cholera 
within twelve to eighteen days. A temperature record 
is maintained for twenty days, and from observing this 
record the virulency of the virus and the potency of the 
serum can in a measure be determined. The following 
chart is the record of a serum test: (See p. 198.) 

This test is not absolute, but it is of value as an indi- 
cator. The test should be repeated if the following con- 
ditions arise. First, if the check pigs should not show 
any evidence of cholera within ten to fifteen days; sec- 
ond, if the check pigs or any of the other six should show 
a constant high temperature beginning on the second, 
third, or fourth day after the test begins; third, if either 



198 



SWINE DISEASES 



RECORD OF SERUM TEST 



Date Begun. 
Date Ended. 



Virus Used, Lot No.. 



.19 

.19__ Quantity Tested. 
Series 







DESCRIPTION 








TEMPERATURES 








Tag 

No. 


Sex 


Wt. 


5/30 
Temp. 


5/ 


31 


6/1 


6t2 


6t3 


6/4 


6/5 


6/6 6/8 


6/9 


6/10 




89 


F 


84 




2 


6 


2.2 


2.4 


3.0 


3.0 


2.4 


2.0,1.4 


1.4 




25 Cc. 


Serum 


2.4 


1.4 


2 Cc. 


Virus 


90 


M 


88 


1.4 


2 


.0 


1.6 


1.8 


1.8 


2.0 


1.8 


2.2 2.0 


2.2 


2.0 


20 Cc. 


Serum 


91 


M 


77 


2.6 


2 





2.4 


2.2 


2.8 


3.1 


4.2 


3.2 2.8 


3.0 


3.2 


2 Cc. 


Virus 


92 
93 


F 
F 


87 
70 


3.8 


3 
3 


2 



2.8 
2.2 


2.7 
2.0 


2.0 

2.6 


2.4 
2.4 


2.4 
2.3 


2.12.2 

1 


2.1 
2.6 


2.2 


15 Cc. 


Serum 


2.4 


2.4 


1.8 


1.6 


2 Cc. 


Virus 


94 
95 


M 
F 


81 
45 


2.8 
3.6 


3 
3 


2 

4 


2.8 
3.6 


2.4 
3.4 


2.6 
4.6 


2.5 
5.4 


2.6 

4.8 


3.0 
5.2 


2.6 
4.0 


2.4 
4.8 


2.6 


2 Cc. 


Virus 


5.2 


2Cc. 


Virus 


96 


M 


47 


3.2 


4 





3.2 


3.4 


3.6 


3.7 


4.2 


4.0 


6.4 


6.2 


6.0 



RECORD OF SERUM TESTS— Continued 



DAYS 


POST MORTEM LESIONS 


6/11 


6/12 


6/13 

1.2 
1.8 
2.8 
2.4 
2.3 
2.8 

5.8 
5.4 


6/14 


6/15 


6/16 


6/17 
Skin 


6/18 

M a 


■3 — 

a a 


1-3 


a 
a 




6ii 


1 
-a 




— 




1.4 
2.0 
3.0 
2.2 
2.0 
2.6 

5.6 
6.0 


1 
1.0 98.6 
1.3 1.2 
2.6 2.2 

2.0 2.2 

2.1 2.4 
2.5 2.6 














1.6 
2.2 


1.0 
1.4 


1.2 
1.6 


98.4 
1.4 
2.6 
2.2 


















3.4 
2.0 


2.0, 2.0 

2.2 2.4 
2.6 2.6 
2.8 2.6 
















2.2 
2.8 


1.3 
2.2 














S 

M 




5.4 
6.2 


5.1 
5.0 


5.2 
6.0 


5.4 
6 2 


died 
5.8 

died 
6.6 


M 

S 


M 
8 


M 
M 


M 
M 


M 
M 


M 


M 
M 


s 

M 



Key to Lesions: S — Slight. M — Well Marked E — Extensive 



PLATE IL 



Fig. 1 




Fig. 2 



Fig. 1. Thrombosis of the liver, showing red and 
white thrombi and thrombi in which decolorization is 
just taking place. 

Fig. 2. Lung showing hemorrhagic areas due to hog 

cholera. 



INFECTIOUS DISEASES 199 

of the first four pigs should die of cholera during the 
time of the test. 

The serum that has been tested and in which the two 
check pigs have died of cholera and the first six pigs have 
shown no visible illness nor any constant rise of tem- 
perature is ready for mixing and bottling, after which it 
is ready for use. The laboratory for mixing and bottling 
must be properly constructed in order that contamination 
of the serum may be reduced to a minimum and the neces- 
sary equipment, such as steriHzers, must be provided. 

For mixing the serum a container must be selected 
that can be sterilized and from which the serum can be 
bottled. 

After thoroughly mixing the serum constituting a 
series it is withdrawn into sterile bottles, the size of which 
will be determined by the demand. The bottles are 
properly sealed, labeled, and wrapped, and until needed 
put back in storage at a temperature not to exceed 50 
degrees Fahrenheit. 

The foregoing description is the general method of 
production of anti-hog-cholera serum. Many Httle fac- 
tors that are of considerable importance have not been 
enumerated. The accompanying illustrations may con- 
vey some idea of the problems of the production of this 
product. The production of anti-hog-cholera serum has 
become of such vast importance to the swine industry 
of the country that Congress has provided means for its 
regulations in order that a potent serum may be obtained. 

The following report of the committee on Uniform 
Methods for the Control of Hog Cholera was adopted 
by the United States Live Stock Sanitary Association 
in Chicago, December, 1913, and is a brief statement of 
the requirements for serum production: 

Serum Production 

Location of buildings. 

• Location to be such that surroundings will not interfere with sanitary 
production and that their operation will not contaminate surrounding 
areas. 



200 



SWINE DISEASES 



Construction of buildings. 

The construction of buildings to be of material that will permit of 
daily cleaning and disinfection, stone, brick, tile, and concrete being 
especially recommended. 

Arrangement of plant. 

1. The arrangement and equipment of buildings to be such as to 
insure the production of a pure and uncontaminated product. 

2. Swine to be kept in separate buildings located a sufficient distance 
from the building containing the bleeding (either virus or serum) and 
hyperimmunizing rooms and in which swine are to be placed for the 
latter purpose only. 




riff. 21.— SERUM CENTBIFUGING ROOM. 
1. A ten-quart centrifuge. 3. a four-quart centrifuge. 

3. The serum bleeding room, the virus bleeding room, and the 
hyperimmunizing room to be separate and distinct rooms. 

4. The preparation of serum, and the preparation of virus from the 
whole blood, to be operations conducted in separate and distinct rooms 
without direct communication with each other or with the foregoing 
not larger than an opening which will permit the transfer of receptacles 
containing the freshly drawn blood, and to be used for no other purpose. 

5. Separate washing and sterilizing rooms to be provided. 

6. The prepared serum and virus to be stored in properly cooled 
rooms. 

7. Swine kept for virus production and the testing of serum to be 
properly isolated so as to reduce to a minimum the danger of spreading 
infection. Separate and distinct feed rooms to be provided for such 
animals. 



INFECTIOUS DISEASES 



201 



8. Mortuary, crematory, abattoir, and desiccating or rendering 
plant operated for utilizing the waste products of the establishment 
to be located so as to prevent contamination from this source. 

9. Necessary dressing and toilet rooms, properly equipped and 
located, to be provided. Also bottling and packing rooms. 

10. Provision for the sanitary disposal of all manure, offal and 

debris. 

Operation. 

1. The operation of serum plants to be under the direct super- 
vision of a competent veterinarian or other professional man whose 
training and experience have fitted him for this work. 

2. Prohibition of the sale of serum and virus produced from animals 
affected with any contagious disease other than hog cholera and of 
any contaminated serum or virus. 





lig. ^3.— STJKKILIZING ROOM. 
1. Electric sterilizer. 3. autoclave. 3. type of utensil used for coUect- 
ing blood. 

3. Provision requiring full and complete records of all steps in the 
manufacture and test of serum or virus. 

4. The label on the container of serum or virus to show the true 
name of the product, the name or number of the manufacturer, the date 
of preparation, or the date after which the manufacture no longer 
guarantees the product, and a serial number to identify the product 
with the records of the establishment. 

Two general methods are utilized in the immunization 

of swine with anti-hog-cholera serum — the serum alone 

method and the simultaneous method. 



202 SWINE DISEASES 

The exact method of administering serum has been 
freely discussed at various associations, and numerous 
articles have appeared in various publications. The 
operator must always provide clean and sterile instru- 
ments. It is true that the instruments become con- 
taminated as soon as used, but at least two needles should 
be provided in order that one may be placed in a disin- 
fecting solution while the other is in use. The syringe 
should be sterilized by boiling after being used for a few 
hours or after a herd has been immunized, before using 
it on another herd. The serum and virus should be in- 
jected deeply into the muscle in order to insure rapid 
absorption. Bad results frequently are the result of 
failure of absorption of the serum or virus that has been 
injected just beneath the skin in the subcutaneous fat. 
Swine that are in filthy, muddy pens should not be in- 
jected because of the probability of infection in the needle 
wounds, and swine that have quantities of mud or filth 
upon their bodies should not be injected. All swine that 
are injected should be reasonably clean, the point of 
injection should be painted with tincture of iodine, and 
the skin should be pinched after withdrawing the needle 
to prevent leakage. 

The serum-alone method produces an immunity for a 
period of from one week to three months, but it does not 
entail any danger of infecting and producing cholera in 
a cholera-free herd and establishing new centers of cholera 
in a community free of the disease. By the proper use 
of serum alone in communities where there are only a 
few centers, cholera could be efficiently controlled. In 
such cases the infected herd and all surrounding herds 
should be immunized and if necessary the process could 
be repeated six weeks later. This method of control is 
not as applicable when several counties of a state, or the 
entire state, is infected. Serum alone, when given in 
large doses, is of considerable value in the incubation 
period of the disease before the animals show visible 
symptoms but after the temperature has risen. The 
judicious use of serum in such cases has saved as high as 



INFECTIOUS DISEASES 



203 



eighty or ninety percent of the exposed herd. The serum 
alone is recommended for immunizing pregnant sows, 
because the simultaneous method frequently produces 
abortion. This method should also be used to immunize 
swine that are to be introduced into healthy, susceptible 

herds. 

The dose of the serum in the serum-alone treatment 
should not be less than thirty cubic centimeters for each 
hundred-pound live weight of hog. 

The simultaneous method is used more extensively 




Fiff. 23-— CHOI-l^KA-lMiMUNK HO(i8. 
There is a firm at the Stock Yards in Chicago manufacturins anti-hos 
cholera serum that makes a business of vaccinatins hoKS, that are 
to be kei)t in the Yards, at $1.00 per hundred pounds and suarantee- 
In-^^theowAers against loss These hogs are kept in the Yards from 
three weeks to ttvo montlis and are driven about from pen to pen 
to clean up the feed left by other animals. They are of course 
continually exposed to virulent infection. 

than the serum alone, because it produces a longer im- 
munity. The dose of serum used in the simultaneous 
method should be fifty percent more than the dose in the 
serum-alone method. The serum and virus must be in- 
troduced separately in different parts of the body. 

This method may be used successfully in exposed 
herds, especially in those swine that do not show a high 
temperature. But the virus should not be given to hogs 
that are showing visible signs of cholera. 

The one serious disadvantage of the simultaneous 
method is the fact that infection is introduced. Good 



204 SWINE DISEASES 

authorities claim that a hog immunized by the simul- 
taneous method does not eliminate the virus unless he 
dies of the disease, but this statement has not been clearly 
proved. Even though the virus is eliminated only in 
case of fatal illness of the immunized hog, the procedure 
is dangerous to say the least. The extensive epizootic 
of hog cholera in Iowa and adjoining states in 1913 bears 
the earmarks of the results of infection from simultaneous 
immunization. 

To say the least, the use of the simultaneous method is 
contrary to good sanitation. 

A so-called double method has been advocated by 
some for the prevention of cholera. It consists of the 
serum-alone immunization, followed ten days later by 
the simultaneous method. This method is quite efficient, 
but is rather expensive. 

In time, the application of serum in the control of 
hog cholera will be rationally adjusted, and this, combined 
with the proper enforcement of efficient sanitary regula- 
tions, will result in diminishing the losses from this dis- 
ease, and the swine industry may then be profitably pur- 
sued. 

SWINE PLAGUE 

Swine plague is a specific infectious disease caused 
by the Bacillus suisepticus and is characterized, except 
in the septicemic form, by a catarrhal and necrotic 
pneumonia, with or without a fibrinous pleurisy. 

The existence of this disease is doubted by some good 
authorities. In various sections of the United States a 
disease of swine, primarily confined to the lung and pleura 
and in its manifestations distinct from cholera, has been 
observed. The same disease has been identified in various 
other countries by other investigators. This disease is 
not so fatal, neither is it so widespread, as cholera. It 
may occur sporadically or enzcotically, but it rarely 
assumes an epizootic form. The percentage of losses in 
affected herds varies from one percent to seventy percent. 

Etiology. — The cause of swine plague is the Bacillus 
suisepticus. This microorganism is a representative of 



INFECTIOUS DISEASES 205 

the hemorrhagic septicemia group. The Bacillus suisep- 
ticus is a short, bipolar-staining, polymorphic, nonmotile 
organism, and does not form spores. The organism 
grows readily on practically all culture media, aerobically 
or anaerobically. It does not liquefy gelatine or coagulate 
milk, and is not stained by Gram's method. 

Its vitality is prolonged for from five to fifteen days 
in soil, feces, and water when not exposed to sunlight, but 
is destroyed in two or three days by desiccation, and is 
easily destroyed by weak antiseptics. The organism is 
killed in twenty minutes by a temperature of fifty-eight 
degrees Centigrade. 

Fowls, rabbits, and guinea pigs are susceptible to the 
pathogenic action of these organisms. The virulence of 
the Bacillus suisepticus is quite variable and is likely to 
vary with suddenness. Intrapulmonary injections into 
swine usually produce multiple catarrhal pneumonia 
succeeded by necrotic pneumonia. 

Source of infection. — The Bacillus suisepticus, like 
the other representatives of this group, are widespread. 
They are frequently found in the respiratory passages of 
normal swine. Their virulence is variable, and it seems 
plausible that some predisposing condition must exist in 
the swine that become affected, or the organism suddenly, 
for some reason unexplained, becomes suflSciently virulent 
to produce the disease. In the most severe outbreaks it 
appears that the virulent organisms are transmitted from 
the diseased to the susceptible swine, or at least the dis- 
ease becomes enzootic in a very short time. 

Channel of entrance. — The usual channel of en- 
trance is by way of the respiratory organs, although it is 
possible that the organism may be successfully introduced 
through the digestive tract or skin. 

Lesions. — The very acute disease is septicemic in 
form and is characterized by petechial hemorrhages in the 
skin and in the serous and mucous membranes. There 
may also be some enlargement of the lymph nodes and of 
the spleen. The usual form of the disease is characterized 
by catarrhal pneumonia, different areas of the lung show- 



206 SWINE DISEASES 

ing different stages of progress of the disease, such as con- 
gestion, red hepatization, gray hepatization, and later 
necrosis in which the necrotic material may be liquid or 
caseous. As a result of the variation of the progress of 
the disease in different areas the affected lung has a 
marbled or mottled appearance. There are some inter- 
lobular infiltrations; the bronchial and mediastinal 
glands may contain hemorrhages or necrotic centers; 
the pleura is usually affected with a fibrinous pleurisy 
with or without adhesions. In the more chronic cases 
the necrotic foci in the lung become more numerous and 
there may be a purulent or septic pleurisy due to the dis- 
charge into the pleural cavity of the necrotic pulmonary 
centers. There will be a diffuse redness of the skin. 

Swine plague is frequently associated with hog cholera, 
and then the various lesions characterizing that disease 
will be present also, all of the lesions being variously 
modified. 

Symptoms. — The period of incubation, at least in 
artificially infected cases, is of short duration, rarely 
exceeding two days. The septicemic type is ushered in 
suddenly with a high temperature, though it rarely ex- 
ceeds 105 degrees Fahrenheit, accompanied by inappe- 
tence, weakness, and little tendency to move. The blush 
of the skin due to hyperemia may be observed. This 
form is rapidly fatal, the course rarely exceeding twelve 
hours. 

The ordinary form of swine plague is evidenced by 
the usual symptoms of pneumonia, such as short, dry, 
spasmodic cough, dyspnea, temperature up to 105 de- 
grees Fahrenheit, a disposition on the part of the affected 
animals frequently to sit on their haunches like a dog, 
mucous or mucopurulent nasal discharge, diminished 
appetite and finally cessation of appetite, and usually 
constipation. As the disease progresses, breathing be- 
comes more difficult and there is extreme weakness and 
emaciation if the affected animals live long enough. 
The blush of the skin is usually present, and there may be 
conjunctivitis. The acute form usually terminates fatally 



INFECTIOUS DISEASES 207 

in about one week, but more rarely the disease becomes 
chronic. 

The chronic form is evidenced by spasmodic cough, 
temperature of about 104 degrees Fahrenheit, poor appe- 
tite, emaciation, and weakness, the animals usually dying 
of exhaustion in from four to eight weeks. 

Diagnosis. — The diagnosis of swine plague is attended 
with considerable diflficulty. The septicemic form can 
be distinguished from the uncomplicated septicemic form 
of hog cholera only by the demonstration in the blood of 
the Bacillus suisepticus or the presence of hog-cholera 
virus by the production of hog cholera by inoculation 
with the filtered blood. 

From the pulmonary form of hog cholera the usual 
form of swine plague is differentiated only by autopsy. 
The lung lesions in hog cholera consist of a typical croup- 
ous pneumonia, but in swine plague they consist of a 
catarrhal pneumonia and, in the later stages, of necrosis 
Pleuritic lesions are frequently present in swine plague. 

Verminous pneumonia can be differentiated from swine 
plague by the chronicity of the attack, the wheezing respi- 
ration, and the demonstration on autopsy of the Stron- 
gylus paradoxus. 

Catarrhal pneumonia is differentiated from swine 
plague by the fact that the former disease occurs only 
in young pigs and is sporadic, and rarely are the necrotic 
centers typical of swine plague found in the lung. Pleuri- 
tic complications are also the exception in catarrhal 
pneumonia. 

Treatment. — Prevention by the enforcement of 
sanitary regulations is much more effective than curative 
treatment. The disease appears to be favored by dry 
weather, which usually insures dusty pens. Wetting of 
the pens with water or some dilute disinfectant prevents 
or diminishes the spread of the disease. 

The use of a bacterin made from the Bacillus suisep- 
ticus, tried out in a few herds, has not given uniformly 
good results, but this method is worthy of further trial 
and it is possible that a polyvalent bacterin prepared 



208 SWINE DISEASES 

from different strains of the different species of the repre- 
sentatives of the hemorrhagic septicemic group would 
be more efficient. 

Immunization by means of a serum prepared by 
repeated injections of a horse with cultures of the Bacillus 
suisepticus has been found partially successful, but the 
immunity thus produced was apparently of short dura- 
tion. This method of immunization will probably not 
come into general use. 

NECROBACILLOSIS 

Necrobacillosis is a name for a group of diseased 
conditions caused by the Bacillus necrophorus and char- 
acterized by inflammation and necrosis. This condition 
is of common occurrence in one form or other in various 
locations in the United States and in other countries. 
The state of Colorado has suffered extensive losses from 
necrobacillosis; in fact, according to Glover, the losses 
from this disease in that state prior to 1912 were greater 
than the losses from cholera. The disease occurs sporadi- 
cally, enzcotically, and rarely as an epizcocic. 

Etiology. — The Bacillus necrophorus is the cause of 
necrobacillosis. This microorganism is universally dis- 
tributed, though the intestinal tract of swine may be its 
natural habitat. The Bacillus necrophorus is pleomor- 
phic, but usually occurs in long threads in cultures and 
in the invaded tissues. It contains granules, particularly 
in old cultures. It is non motile and does not form spores. 
It is a strict anaerobe and grows well in serum agar, 
bouillon, and milk. A pungent, disagreeable odor is 
evolved from the cultures, and may also be recognized 
in the lesions. It stains readily with practically all of 
the aniline dyes but not with Gram's stain. 

The Bacillus necrophorus produces disease by products 
that it elaborates and eliminates into the tissue. This 
microorganism is pathogenic for practically all animals; 
but as a rule it is only a secondary invader, the tissue 
resistance having been diminished by previous disease 
process or by injury. Inoculations of cultures of the 



INFECTIOUS DISEASES 209 

Bacillus necrophorus produces necrosis, or abscess forma- 
tion, in cattle, sheep, swine, and horses. 

Source of infection. — The Bacillus necrophorus 
inhabits the digestive tubei of swine and, less frequently, 
the digestive tube of other animals; therefore the micro- 
organism is found in the feces of practically all animals. 
Soil, yards, pens, floors — in fact, practically all of the 
surroundings — easily become contaminated with fecal 
matter, and the disease may be obtained from anything 
that has been contaminated with feces. Infection is 
usually indirect, although the Bacillus necrophorus may 
be transmitted from an affected to a healthy animal by 
contact. 

Channel of entrance. — This infective agent may be 
successfully introduced into the susceptible swine in food 
or drink by way of the mouth, upon inhaled dust particles 
by way of the respiratory organs, or it may be introduced 
through abrasions of the skin, and, more rarely, into the 
genital organs diring copulation. 

Lesions. — The Bacillus necrophorus is capable of 
invading practically any tissue of the body, and the 
lesions produced so closely resemble each other that one 
general description will suffice. The lesion consists of 
a coagulation necrosis, the necrotic material later becom- 
ing caseated. The local lesion has a tendency to become 
larger, due to the infiltration of the surrounding tissue 
with the products of the Bacillus necrophorus. The 
infection, and therefore the lesions, may occur elsewhere 
in the body, due to metastasis. There may be general 
emaciation due to absorption of the products of the 
Bacillus necrophorus, and tissue destruction. 

The local specific lesion is a sharply circumscribed 
yellowish or brownish area containing a homogeneous, 
dry, mealy, or cheese-like substance from which a pungent 
and disagreeable odor emanates. Microscopic examina- 
tion of a section of one of these areas reveals a central 
mass of tissue debris composed of disintegrating and de- 
stroyed cells which do not stain. Surrounding the 
necrotic area is a zone made up of leukocytes, damaged 



210 SWINE DISEASES 

tissue cells, and considerable numbers of Bacillus necro- 
phorus filaments arranged in bundles. The surrounding 
tissue evidences a severe reaction by hyperemia, and the 
presence of large numbers of leukocytes and a few Bacilli 
necrophorus. t.J 

^' Necrobacillosis assumes many different forms, the 
most common of which are necrotic stomatitis, enteritis, 
rhinitis, pneumonia, hepatitis, splenitis, vaginitis, and 
dermatitis. 

Necrotic Stomatitis 

Necrotic stomatitis is probably the most common 
form of necrobacillosis. It is of frequent occurrence in 
suckling pigs. 

Lesions and symptoms. — The inflammation usually 
begins at the margins of the gums. The successive 
changes in the affected areas are as follows. The surface 
is red or bluish red, becomes tumefied, is very sensitive, 
and bleeds easily. Two or three days later the area be- 
comes yellowish white or even brown in color and of a 
mushy consistency, and usually sloughs, leaving an 
eroded surface which is covered by a coagulated necrotic 
tissue and appears as a diphtheritic membrane. The 
surrounding tissue becomes red, tumefied, and sensitive. 
The disease process gradually extends and ultimately 
becomes confluent, forming large eroded areas. A 
similar process frequently affects the lips simultaneously. 

The affected pigs frequently attempt to nurse, but the 
gums are so sensitive that they obtain little nourishment. 
Pigs may transmit the disease to the teats of their mother 
by nursing. There is salivation and champing of the 
teeth. Upon inspection the foregoing lesions are 
observed and a peculiar disagreeable odor is also noted 
which may permeate the air and be recognized at a 
considerable distance. As the disease progresses the 
discharged saUva becomes bloody and contains shreds of 
tissue. 

The course of this disease varies from a few days in 
the acute form to several weeks in the chronic form. 



[NFECTIOUS DISEASES 211 

Diagnosis. — The identification of necrotic stomatitis 
is not difficult if the typical necrotic lesions are observed 
and the peculiar offensive odor is recognized. 

Treatment. — In the early stages the treatment of 
the cases may be successful, but in the advanced stages 
the disease usually proves fatal regardless of treatment. 
The most successful treatment consists in washing the 
oral cavity and applying upon the eroded areas one- 
percent solutions of silver nitrate or three- to five-percent 
solutions of zinc chlorid. Local treatment should be 
repeated frequently. 

Necrotic Enteritis 

This is frequently a sequel to necrotic stomatitis, the 
infection passing along the digestive tube in the patches 
of sloughed necrotic tissue or directly from the intestinal 
content. Necrotic enteritis is relatively common in 
swine. It frequently accompanies hog cholera. 

Lesions. — ^The lesions of necrotic enteritis are most 
common in the mucous membrane of the intestine near 
the ileocecal orifice. The lesion is very similar to that 
of necrotic stomatitis, except that here the necrotic tissue 
usually remains intact and becomes coagulated and 
mealy or caseous. This adhering pseudomembrane may 
occur in small, scattered, circumscribed areas, or prac- 
tically the entire mucous membrane may be involved. 
Microscopically the surface epithelia in the affected areas 
are found disintegrated and commingled with the coagu- 
lated debris upon the mucous surface. 

Symptoms. — This condition frequently exists to a 
limited degree without manifestation of any symptoms. 
In the cases where the lesions are more extensive there is 
indigestion, colicky pains, and diarrhea. Later the appe- 
tite may be diminished or the desire for food may cease; 
the animals become unthrifty, emaciated, and weak. 
The course varies with the intensity of the disease; it 
may run a rapid course or it may become chronic. It is 
rarely fatal. 



212 SWINE DISEASES 

Treatment. — Proper dieting and the provision of 
good sanitary quarters must first be considered. The 
use of castor oil to clean the bowel of offending material 
is a good practice. Intestinal antiseptics, too, may be 
used to good advantage. 

Necrotic Rhinitis 

This condition is usually associated with necrosis of 
the snout and frequently also of the lips, and is of rather 
common occurrence in small pigs. It is one of the con- 
ditions that constitutes the disease called sniffles. Sniffles 
also includes catarrhal rhinitis, particularly those cases 
in which deformity of the snout and nasal cavities occurs, 




Fiff. 24.— NECROBACII.T.OSIS. 

and those cases of rickets in which there is involvement 
of the nasal and facial bones, causing more or less 
deformity. 

Lesions. — Necrobacillosis of the schneiderian mucous 
membrane and the snout is characterized by the same 
lesions that are characteristic of necrotic stomatitis, 
except that here bone tissue is frequently involved, 
resulting in fibrinous proliferation and deformity of the 
parts. 

Symptoms. — The affected animals have a tendency 
to root considerably in their food, but they eat little. 
The characteristic symptom consists of a peculiar blow- 
ing noise. The animals sneeze, and occasionally expel 



INFECTIOUS DISEASES 213 

bloody material containing shreds of tissue. The snout 
becomes enlarged and the face bulging, this condition 
frequently being called an elephant head. 

Treatment. — It is not possible to efficiently treat 
these cases because of the difficulty of applying medica- 
ments to the lesion and further because of the destructive 
changes in the bones of the nose and face. 

Necrotic Pneumonia 

Necrotic pneumonia is frequently an associated con- 
dition of necrotic rhinitis, the infection taking place by 
the inhalation of necrotic particles from the nose. 

Lesions. — The same general coagulation necrosis 
type of lesions that characterizes necrobacillosis are 
observed also in necrotic pneumonia. 

Symptoms. — Manifestations of the disease are similar 
to those of croupous pneumonia, though evidence of septic 
intoxication is more pronounced than in the latter. The 
very offensive odor of the expired air characterizes pul- 
monary necrobacillosis. 

Treatment. — Treatment other than providing good, 
nourishing food and sanitary surroundings is of little 
or no avail. 

Necrotic Hepatitis 

Hepatic necrobacillosis is not of common occurrence, 
but some cases have been observed. It is usually sec- 
ondary to necrotic enteritis, the infection passing through 
the portal system and metastasizing in the liver. 

Lesions. — The lesions consist of sharply circum- 
scribed grayish-white areas varying in size from that of a 
pinhead to a silver dollar. These areas may be sur- 
rounded by a fibrous capsule. The density or consistency 
of the lesion depends upon its age. It may be of the 
same consistency as the surrounding Hver, it may be dry 
and mealy, or, if the animal recovers, it may become 
calcareous. These areas may not cause any irregularity 
in the size or shape of the liver or the lesion may assume 
the nodular form, the nodules projecting from the surface 
of the liver. The surface nodules have a raised border 



214 SWINE DISEASES 

and a depressed center, and are quite characteristic in 
appearance. 

Symptoms. — No definite symptoms have been at- 
tributed to hepatic necrobacillosis other than general 
digestive derangement. These cases are diagnosed at 
autopsy. 

Treatment. — The location of the lesions and the 
nature of the process practically eliminate the possibility 
of successful treatment. 

Necrotic Spleenitis 

Splenic necrosis is a rather common condition in 
swine. It may be caused by other agencies than the 
Bacillus necrophorus, but from investigations thus far 
conducted it appears that the most frequent cause of 
necrosis of the spleen is the Bacillus necrophorus. This 
condition is commonly associated with the use of a 
contaminated hog-cholera virus. The infection is carried 
in the blood to the spleen. 

Lesions. ^ — The necrotic centers in the spleen are 
usually encapsulated, the density of the capsule varying 
with the length of duration of the process. As a rule, 
the centers are in the form of nodules. They are of a 
grayish-white color and usually have a depressed center 
and a raised border. In size these foci vary from masses 
half an inch in diameter to irregular masses from one to 
three inches in diameter. There may be only a few 
centers, but usually there are many; in some instances so 
numerous are they that it is diflScult to identify any nor- 
mal splenic tissue. The non-encapsulated lesions are 
dirty-white centers and give the appearance of having 
been painted in the splenic tissue. 

Symptoms are indistinct, and treatment cannot be 
applied. 

Vaginal Vulvar and Preputial Necrosis 

Necrotic vaginitis and vulvitis occurs, but is not 
prevalent. Infection probably gains entrance through 
abrasions produced at the time of parturition or copula- 
tion or, more rarely, by means of accidental traumatic 



INFECTIOUS DISEASES 



215 



wounds. The lesions consist of tumefaction, redness, 
and sensitiveness, followed by necrosis. The necrotic 
tissue may become desiccated and slough, or it may be 
converted into a mushy mass. The erosion of the vulva 
may destroy the vulvar tissue and even the anal tissue. 
Dense masses of fibrous tissue usually develop in the 




Fig. 25. — FAT NECROSIS (Omentum). 
A. Normal fat. B. areas of necrosis. 



perinecrotic zone, which later cicatrizes and produces 
various distortions of the vulvo-anal structures. 

Infection of the prepuce may gain entrance through 
abrasions produced by inflammation that has resulted 
from irritation from urine, screw worms, or similar 
causes. Infection may also be favored by traumatic 
injuries of various kinds. The lesions are of the same 



216 SWINE DISEASES 

general nature as those observed in vulvitis. The prepuce 
occasionally becomes entirely destroyed, and sometimes 
the penis becomes involved. 

The vulvar and preputial lesions sometimes interfere 
wiih, and even inhibit urination, resulting in retention of 
urine. In such cases in the male the sheath may become 
enormously distended with urine. 

Treatment. — Treatment is confined to the local 
application of some penetrating disinfectant. Those 
lesions that become necrotic are removed in order 
that the disinfectant may have free access to the invaded 
tissue. Adhesions and other conditions that obstruct the 
urine should be corrected, at least temporarily, in order 
that the urine may be voided and thus uremic poisoning 
prevented. 

Necrotic Dermatitis 

Necrotic dermatitis, aside from the type affecting 
the lips, vulva, and prepuce, is sometimes encountered. 
It is of most frequent occurrence in young pigs, and affects 
any portion of the body. Infection of the Bacillus 
necrophorus into the skin is probably possible only through 
abrasions and wounds. 

Lesions. — The lesions are practically the same as in 
other superficial necrobacillosis. Not infrequently large 
areas slough, leaving irregular denuded surfaces. This 
condition is frequently fatal, particularly in those cases 
having extensive infection where absorption of the prod- 
ucts is sufficient to insure systemic disturbance. 

Treatment. — Treatment consists of removing 
necrotic tissue and applying some antiseptic that will 
readily penetrate the infected area. The treatment 
must be persistent, as relief cannot be obtained from 
one application. 

Unusual Forms of Necrobacillosis 

Necrobacillosis sometimes occurs in the various 
structures of the eye. This is a serious condition, as the 
agents used in combating the Bacillus necrophorus have 
to be used in such concentration that they are injurious 



INFECTIOUS DISEASES 217 

to the eye. The usual outcome of ocular necrobacillosis 
is destruction of the eye, and if both eyes are involved 
the animal becomes blind and usually has to be destroyed. 

Necrobacillosis as a sequel of castration has been 
previously discussed (See p. 120). 

Necrobacillosis is a disease that may affect practically 
any and all tissues of swine and is of considerable economic 
importance. The most common forms of the disease 
are necrotic stomatitis and enteritis, and necrosis of the 
sheath. 

TUBERCULOSIS 

Tuberculosis is a specific infective disease caused by 
the tubercle bacillus and characterized by the formation 
of tubercles. 

History. — Tuberculosis has been recognized from 
the remotest time in the history of man as a prevalent 
disease of mankind. In 1689 the tubercle was identified 
by Morton as the typical lesion of tuberculosis. Various 
investigators have given additional knowledge on the 
subject of tuberculosis. In 1865 Villemin proved the 
infectiousness of the disease, while Koch discovered the 
tubercle bacillus in 1882, thus establishing firmly the 
theory of the infectiousness of tuberculosis. The study 
of tuberculosis has been advanced and its recognition 
clinically has been made possible by the use of tuberculin 
which was discovered by Koch in 1890. In 1901 he 
startled the scientific world by announcing at the tubercu- 
losis congress in London that human and bovine tuber- 
culosis were separate and distinct diseases, a statement 
that was responsible for the organization of different 
scientific bodies that, after careful investigation, reported 
that although there may be some slight difference between 
the tubercle of human and bovine origin, the disease 
produced is the same and that the disease is inter- 
transmissible between animals and man. 

Occurrence. — Tuberculosis is becoming very preva- 
lent among swine. This is due to the fact that the dairy- 
ing industry is becoming more extensive and the byprod- 



218 SWINE DISEASES 

ucts of milk are used for swine feed. A relatively large 
percentage of dairy cattle is tuberculous, and the infection 
gains entrance to the milk on filth that is contaminated 
with infected discharges, such as saliva and feces. The 
organism may also be eliminated direct from the mammary 
gland into the milk. 

Swine from some sections of the United States have 
been found by experience to be so extensively tuberculous 
that some packers will buy them only subject to post- 
mortem inspection. 

In Germany from 2.46 to 2.81 percent of swine 
slaughtered at abattoirs were condemned on account of 
tuberculosis. The disease is very prevalent in Belgium, 
France, Norway, and Sweden, and porcine tuberculosis 
is a common disease in the British Isles. According to 
the annual report of the Bureau of Animal Industry for 
1911, 29,920,260 carcasses of swine were inspected in 
abattoirs, and of that number 31,517 carcasses and 870,361 
parts were condemned on account of tuberculosis. The 
disease is becoming more extensive in swine in the United 
States and should receive more consideration than it 
does, for the economic loss annually is enormous. 

Etiology. — The cause of tuberculosis is the tubercle 
bacillus or the Bacillus of Koch. It is a rod-shaped 
organism from 1.5 ta 4 microns long and .3 to .5 micron 
in width, and is usually curved or slightly bent. It 
may contain granules or the body may be uniform. It 
is nonmotile and does not form spores. This organism 
is covered with a waxlike substance which renders it more 
diflBcult to stain than ordinary bacteria, but after the 
organism has been stained, which can be accomplished 
by applying steaming carbolfuchsin for five minutes, it 
retains the stain even when subjected to the action of 
acids; for this reason it has been called an acid-fast 
bacterium. It is an aerobe, and grows with relative 
slowness. It grows luxuriantly in egg albumen culture 
medium, and fairly well on glycerine agar and in glycerine 
bouillon. Tubercle bacilli from different sources manifest 
different cultural characteristics, and on this basis some 



PLATE III. 



Fig. 1 




Fig. 2 



Fig. 1. A typical tuberculous liver. 

Fig. 2. Vertebrae showing tuberculous bone lesions. 



INFECTIOUS DISEASES 219 

have claimed four varieties of tubercle bacilli, namely, 
human, bovine, avian, and reptilian. The bovine and 
human types have been encountered in swine. 

The tubercle bacilli are very resistant to external 
injurious influences. This resistance is probably due to 
the waxy coat they possess. Direct sunlight destroys 
them when freely exposed for twenty to thirty minutes, 
but they retain their vitality and virulence for from ten 
to twenty days when exposed to diffuse daylight. When 
desiccated and not exposed to light they may retain 
their virulence for four months or even longer. In 
decomposing tubercular tissues they remain virulent for 
a long time. In milk they retain virulence for ten days. 
Dry heat at 212 degrees Fahrenheit destroys them in one 
hour; moist heat at the boiling temperature will destroy 
them in fifteen minutes. They are also destroyed by 
chemical disinfectants, the length of time for exposure 
depending upon the concentration of solution and the 
nature of the tissue or discharge incorporating the bacilli. 
Gastric juice does not destroy the tubercle bacilli, and 
bile has little or no injurious effect upon them. 

The inoculation of healthy, susceptible animals with 
virulent bacilli produces tuberculosis, the extent of the 
lesions produced depending upon the virulence of the 
bacilli injected and upon the resistance of the inoculated 
animal. 

Source of infection. — Tubercule bacilli are ehmi- 
nated from the affected animals, at least when there are 
open lesions in organs, the secretions or excretions of 
which pass to the outside world. Thus the tubercle 
bacilli are eliminated in the feces from animals having 
tubercular ulcers of the intestinal mucosa. Open tu- 
berculous lesions of the respiratory tract would permit of 
the elimination of the tubercle bacilli in the discharge 
from the air tubes and also in the feces, for the chances 
are that the pharynx would become contaminated by 
the pulmonary or tracheal discharge and this infection 
would be carried with food or drink and ultimately pass 
from the body in the feces. Tubercle bacilli from lesions 



220 SWINE DISEASES 

in the liver or pancreas may also be eliminated in the 
feces. 

Tubercle bacilli from open tubercular lesions of the 
urogenital organs are eliminated in the urine, seminal 
fluid, or other discharges from these organs. Infection is 
directly eliminated from open, cutaneous, tuberculous 
lesions, and tubercle bacilli may be eliminated in the 
milk, especially if tuberculous lesions exist in the mammary 
gland. 

The dissemination of tubercle bacilli in the body and 
the possibility of their elimination through any channel 
is facilitated by leukocytes. Thus tubercle bacilli in the 
lung may be incorporated and retained by leukocytes 
that are later eliminated by the mammary cells, and the 
milk become infected even though the mammary gland 
contain no tuberculous lesions. 

From the foregoing it is evident that any of the dis- 
charges of tuberculous animals may contain the tubercle 
bacilli. In the United States and in practically all other 
countries tuberculosis of cattle is prevalent, particularly 
among cattle used for dairy purposes. 

The most frequent source of porcine tuberculosis is 
from tuberculous cattle. Swine become infected from 
infected cow's milk, feces, nasal discharges, and the car- 
casses of tuberculous cattle that are given them for food 
A limited number of swine become infected from garbage 
that contains the human tubercle bacilli. This has been 
especially observed in swine fed upon garbage from tuber- 
culosis sanitaria, or hotels. An occasional case of uterine, 
ovarian, or testicular tuberculosis is the result of direct 
infection by copulation. It is possible that infection 
may be transmitted in the exhaled air from infected to 
healthy swine. 

Channels of entrance. — The most frequent channel 
of entrance of the tubercle bacilli in swine is the digestive 
tube, the infection being introduced in food or water. 
An occasional case may become infected by the inhalation 
of the bacilli and by direct transmission through the geni- 
tal organs. Mammary tuberculosis may be the result 



INFECTIOUS DISEASES 221 

of cutaneous infection or it may be transmitted from 
elsewhere in the body. 

The transmission of the tubercle bacilli from the 
mother to the fetus is possible but it is of rare occurrence. 
But a weakened condition or susceptibility to the disease 
may and frequently is transmitted from the mother to 
the fetus. 

Lesions. — The typical initial lesion of tuberculosis is 
the tubercle which has been aptly defined as a nonvascular 
nodule composed of leukocytes, endothelial, giant 
and connective tissue cells, with a tendency for the 
central part of the nodule to undergo necrosis. There 




Fig. 26.— TUBERCULOSIS OF THE TONGUE. 
A. Normal muscle. B. tuberculous lesions. This is a rare condition 
in swine. 

may be slight variation in the tubercle in different ani- 
mals, due to variation of susceptibility of the animal and 
variation of the virulency of the infecting bacilli. The 
typical lesion may also be materially modified by second- 
ary lesions. Tuberculous lesions may occur in any tissue 
or organ, but lymphoid tissue is most frequently affected. 
The tubercle bacilli and their products are the causa- 
tive factors in the formation of a tubercle. Having 
lodged in a tissue favorable for their growth and develop- 
ment, the bacilli begin to multiply and to eliminate 
products that stimulate the surrounding connective tissue 
and endothelial cells to increase in number, and at the 



222 



SWINE DISEASES 



same time exert a positive chemotactic action upon the 
leukocytes. In swine there is a very marked chemotactic 
action and limited stimulation of connective tissue. 
The typical porcine tuberculosis tubercle is; largely com- 
posed of leukocytes and has little fibrous tissue. 

Tubercles grow because of the increased accumulation 
of leukocytes and the formation of a small quantity of 
fibrous tissue. The tubercle contains no blood vessels; 
that is, it is nonvascular, although in the early stages 
there may ; be a hyperemic zone around the tubercle. 
This hyperemic zone is the result of irritation in the tissue. 




Fig:, 37.— TUBERCULOSIS OF THE SKIN. 

A. The skin showing: caseo-calcarous lesions. B. subcutaneous fat. 
C. muscle. ' 



the tubercle formation causing a tissue reaction. As the 
tubercle becomes larger, due to the accumulation of 
leukocytes on the margin, the central part begins to 
degenerate. 

Porcine tubercular lesions are characterized by en- 
largement of lymphatic glands, the formation of tubercles 
of variable sizes in or upon serous membranes and within 
the substance of glandular organs, bones, and other 
connective tissues. The tubercles produce increased 
density of invaded soft tissues and are, therefore, easily 
detected except in very recent infection. The tubercular 
nobules in the early stages present about the same color 
as the surface of the tissue invaded. In sectioning the 



[NFECTIOUS DISEASES 223 

tubercle the central portion is caseous and slightly yellow, 
or fibrous and white. Sometimes there is a combination 
of both conditions, and occasionally the tubercles contain 
calcareous granules. The central portion of porcine 
tubercles rarely contains liquefied necrotic tissue. 

Microscopically, porcine tubercular lesions are always 
cellular in the beginning, the cellular tubercles being 
fairly constant in structure, regardless of the tissue in 
which they occur. The center is at first represented by 
a mass of lymphoid cells, the other cellular elements 
occurring as the tubercle develops. 

Necrosis, or fibrosis, succeeds the cellular stage in 
the porcine tubercular lesion. Necrosis of tubercles is 
probably the result of the activity of virulent bacteria or 
the low resistance of the infected animal. The necrotic 
center may be surrounded by a cellular zone (lymphoid 
and endothelial cells), or it may be surrounded by fibro- 
blasts. The necrotic material is invariably caseated and 
later becomes calcified. 

Fibrous lesions vary from the formation of small 
quantities of fibrous tissue to dense fibrous centers. 
They are probably produced by bacteria of low virulence, 
or occur in animals having a marked resistance. The 
central portion of the fibrous lesion may become calcified. 

The so-called arbor vitse gland is a fibrous center in 
which the fibrous tissue is arranged similarly to the trunk 
and branches of a tree, hence the name. In the hog, 
this lesion is observed in the cervical lymph nodes. The 
Bacterium tuberculosis has been demonstrated in about 
thirty per cent of arbor vitse glands. 

The lesions of porcine tuberculosis are in brief either 
cellular, necrotic, and calcified tubercles, or cellular, 
fibrous, and calcified tubercles. The lesion is always 
nonvascular, as in other animals. 

Tubercular lesions are most common in the digestive 
viscera. The Hver and spleen frequently contain caseous 
nodules. 

Pulmonary porcine tuberculosis manifests itself either 
by a few or many cheesy foci or by a few large centers. 



224 SWINE DISEASES 

There may be a general caseous pneumonia associated 
with more or less pleurisy. 

Tubercular involvement of the nervous tissue occurs 
in swine, but is relatively rare. One case has been ob- 
served in which a tubercular center occurred in the 
cerebral tissue. Tuberculosis of the meninges may be 
local and circumscribed or diffuse and quite general. 

Osseous tuberculosis is of common occurrence in 
swine. It is found especially in the vertebrae. 

Symptoms. — Tuberculosis is essentially a chronic 
disease. The onset is usually so insidious that no ab- 
normality is suspected, and the usual clinical examination 
of swine is not suflficient to predicate a diagnosis because 
the symptoms are so indistinct. Lymph-gland involve- 
ments result in tumefaction. The enlarged glands are 
not pathognomonic of tuberculosis. 

Tubercular invasion of the digestive organs produces 
indigestion. The digestive derangements develop slowly 
and usually only in young pigs. They become unthrifty 
and emaciated as the disease progresses. 

Pulmonary tuberculosis is evidenced by a dry, short, 
suppressed cough and by some diflBculty of breathing. 
The cough becomes more aggravated, and the animals 
become weak and thin and have a rough coat. 

Tuberculosis of the brain, or meninges, is not common 
and the symptoms evidenced will depend upon the loca- 
tion of the lesion. 

Osseous tuberculosis is associated with interference 
of locomotion and tumefaction of the affected bone. 

The length of the course of tuberculosis is variable- 
In young pigs it may produce fatal termination in from 
two to three months after the onset. Older swine rarely 
die of tuberculosis, as the disease assumes a chronic form 
in them and they are usually marketed before the dis- 
ease has manifested itself clinically. 

Diagnosis. — The clinical diagnosis of this disease is 
practically impossible without the use of the tuberculin 
test. The lesions may be identified and the disease can 
therefore be recognized by autopsy. 



PLATE IV. 




•••f "*«»H 




Fig. 1 



Fig. 2 





Fig. 1. Spleen showing calcified tubercles sur- 
rounded by hyperemic margins. 

Fig. 2. Lung showing areas of normal tissue, areas of 
red hepatization and caseo-calcareous, tubercular areas. 



INFECTIOUS DISEASES 



225 



The intradermal tuberculin test is most applicable to 
swine. This test is made by the injection into the 
dermis at the base of the ear of from three to five minims 
of ordinary tuberculin.* The reaction consists of a 
dense swelling at the point of injection and becomes 
most prominent on the second or third day after injection. 



B 




B 







Fiff, 28.— TUBERCULOSIS OF THJK rUEUKA. 
A. Rib. B. masses of tubercles. 



The subcutaneous tuberculin test may be used, but 
it is not as applicable to swine as it is to cattle. The 
ophthalmic test may also be employed in swine. 

Microscopic examination may be made of the various 
discharges for the purpose of identifying the tubercle 

♦The Bureau of Animal Industry have issued an order that all swine used for tail 
bleeders in serum production must be tested with especially prepared intradermal 
tuberculin. The object of this order is not clear, as the ordinary tubercuhn is as 
efficient as special intradermal tubercuUn.- 



226 SWINE DISEASES 

bacilli. In making this test it must be remembered that 
there are other acid-fast bacteria and further that the 
absence of tubercle bacilli in the preparations examined 
is not positive proof of the absence of the disease. 

Animal inoculations may be resorted to, particularly in 
cases in which no tuberculin test has been made and there 
is a dispute as to the nature of the lesions found. 

Treatment. — Curative treatment is of no value in 
porcine tuberculosis. The only rational method is to 
sell the affected swine subject to the post-mortem inspec- 
tion findings. In this way some value will be obtained 
by the original owner, there will be no loss to the packer, 
and no danger to the consumer. 

Tuberculosis is a preventable disease and the losses 
from it could be avoided, or at least materially dimin- 
ished, by proper control of tuberculosis in cattle. With 
our present farm methods the eradication of porcine 
tuberculosis cannot be accomplished until the disease 
is eradicated in cattle. The judicious use of skimmed 
milk, including pasteurizing milk from suspected cows, will 
materially diminish tuberculosis in milk-fed swine. 
The tuberculin testing of steers or other cattle and the 
elimination of all reactors will prevent the introduction 
of tuberculosis in swine that follow cattle in the feed lots. 
Cooking of garbage will prevent the dissemination of 
tuberculosis to swine. Denver garbage is cooked and 
fed to swine, the infection of tuberculosis and hog 
cholera as well is thus eliminated. 

OMPHALOPHLEBITIS, PYEMIC ARTHRITIS 
(NAVEL ILL) 

This is an acute infectious disease of recently farrowed 
pigs characterized by inflammation of the umbilical 
tissues and suppurative arthritis. 

Navel or joint ill has prevailed more or less extensively 
since the dawn of history. In some years this disease is 
responsible for the loss of a large percentage of the young 
pigs produced in certain communities. The disease 



INFECTIOUS DISEASES 227 

occurs enzootically and as an epizootic, sporadic cases 
being rare. 

Etiology. — This condition is caused by infection, but 
the specific exciting cause has not been positively identi- 
fied. The Staphylococcus pyogenes aureus has been 
isolated from the lesions and was apparently present in 
practically a pure culture. A Streptococcus appears to 
be the exciting cause in some cases, and in other cases the 
colon bacillus or some of its derivatives have been identi- 
fied. Bacillus pyocyaneus sometimes causes this con- 
dition. The young animals are predisposed to the 
various types of infection by filthy surroundings and 
improper care. Some breeders claim that if the sows 
are permitted to farrow in clean quarters, and are main- 
tained and fed in the proper way, that the pigs will not 
contract this disease. 

There is evidence of the transmission of the disease 
in utero from the dam to the foal in horses, but such 
evidence has not been obtained in swine. 

The infection gains entrance through the thrombi in 
the umbilical vessels. The infecting organisms extend 
in the thrombus, ultimately reaching the blood stream, 
by means of which they are disseminated throughout 
the body. 

Lesions. — The manifestations of this disease are 
variable and depend upon the number and virulency of 
the infecting organism and their location in the body. 
The typical lesions consist of omphalitis and suppurative 
arthritis. Inflammation of the umbilical vessels may be 
limited or there may be an accumulation of pus, the 
inflammation being a typical suppuration and abscess 
formation. The lesions of the joints are variable. 
There may be a mild synovitis with limited or extensive 
infiltration and tumefaction of the structures surrounding 
the synovial membrane, in which cases the synovial mem- 
brane is injected and tumefied. There is an increased 
amount of fluid and it will be turbid and perhaps contain 
flakes of coagulated material. In other instances the 
synovial membrane will be distended with accumulated 



228 SWINE DISEASES 

pus and surrounding tissues may also be infiltrated with 
pus. 

Metastatic abscesses may occur in various organs, as 
in the liver and spleen. If the infection extend to the 
bladder there will also be a purulent cystitis. 

Symptoms. — The symptoms usually appear in the 
first week of life, although they may occur in the^second 
or third week after farrowing. The affected pigs will be 
lame and indisposed to move. On examination one or 
more of the articulations are found to be swollen and 
sensitive, the tarsal joints being most frequently involved. 
There may be diarrhea. The course of the disease is 
usually brief, the pigs as a rule dying on the second or 
third day. 

Treatment. — Curative treatment is of little value. 
The disease may be prevented by providing clean pens 
and keeping them clean before and after farrowing. 

SPASMS OF THE DIAPHRAGM (THUMPS) 

Thumps is a condition caused by violent contractions 
of the diaphragm, and is relatively common in small pigs. 

Etiology. — This condition is apparantly due to some 
interference of the diaphragm, and is usually associated 
with overloading of the stomach or insufficient exercise. 

Symptoms. — There is a sudden jerking of the flanks. 
This symptom is very prominent when it occurs in a pig 
that is standing quietly, and there may be an accompany- 
ing sound that is quite distinct. There is an irregularity 
in the frequency of the contractions; sometimes they 
occur in rapid succession, followed by a period of appar- 
ently a normal condition, then another series of con- 
tractions. Exercise and a full stomach aggravate the 
condition. The pig may become weak and emaciated. 
The course of the disease varies from one week to two or 
three months. 

Treatment. — Good nourishing food and plenty of 
exercise are usually sufficient to correct spasms of the 
diaphragm. Small doses of from two to three drops of 
tincture of opium, administered with oil, will usually give 
temporarj^ relief. 



INFECTIOUS DISEASES 229 

Rabies 

Rabies occurs in swine, but is not prevalent. It may 
occur enzootically, but is much more likely to affect only 
one animal, or few animals at most, in any one locality. 

Etiology. — Rabies is caused by a virus, but the exact 
nature of this virus has not been determined more than 
that it is filterable. Recently it has been successfully 
cultivated. 

Source and manner of infection. — The usual 
source of rabies in swine is from an infected animal, 
usually a dog. Rabid dogs meandering through the 
country occasionally attack swine, biting and thus infect- 
ing them. 

Lesions. — Gross lesions are absent in swine that have 
died of rabies. Foreign substances may be found in the 
stomach, but swine have a habit of consuming almost 
anything and therefore foreign bodies in the stomach 
has little significance. Microscopically, Negri bodies 
are found in the cells of the amnion horn, and also in the 
cells of the cerebellar cortex. These bodies are the same 
in swine as in other animals. 

Symptoms. — Affected swine usually become excitable 
and show sexual desire, and they may become vicious 
and attack other animals or man. They have a depraved 
appetite, or there may be inappetence. These symptoms 
will become more aggravated for two or three days, then 
the animal becomes depressed and paralysis of various 
groups of muscles appears. The affected animals may 
be depressed from the beginning, soon evidence more or 
less of paralysis, and finall}'^ assume a comatose state 
prior to death. 

Diagnosis. — Diagnosis cannot be made positive by 
clinical examination, although if the history shows con- 
tact with a rabid animal from ten days to four weeks 
before the symptoms appeared one could diagnose the 
case as suspected rabies. A positive diagnosis can be 
made only by the finding of Negri bodies by microscopic 
examination, or the reproduction of the disease by inocu- 



230 SWINE DISEASES 

lation of a laboratory animal with a small quantity of 
the brain tissue of the animal in question. 

Treatment. — Curative treatment has always been 
considered futile. Recently the use of quinine has, 
according to reports, given good results in cases of rabies 
in dogs. Other investigators have failed to obtain 
beneficial results from the use of quinine in experimentally 
inoculated cases of rabies. If valuable animals are 
known to have been bitten by a rabid dog it may be 
given the Pasteur treatment and thus the development 
of the disease prevented. 

Foot and Mouth Disease. (Aphthae Epizooticae) 

This is an acute, infectious, transmissible disease, 
primarily affecting cattle and sheep. It also affects 
hogs, goats, more rarely horses, dogs and other aninials. 

This disease is quite prevalent in some European 
countries and it has appeared in the United States on six 
different occasions: In 1870, 1880, 1884, 1902, 1908 and 
1914. 

Etiology. ^ — Foot-and-mouth disease is produced by 
one of the so-called filterable viruses, which up to the 
present time has not been successfully cultivated outside 
of the animal body. The virus exists especially in the 
serous fluids of the vesicles in the mouth, from which it 
gains entrance to the saliva and thus to the soil and food 
from the salivary secretions. The vesicular lesions are 
also found on the feet and thus the virus also gains en- 
trance to soil, bedding and food, from which other animals 
can easily obtain infection. There appears to be little 
doubt but what the virus is eliminated from the body in 
all excretions. The exact length of time the virus will 
retain its vitality outside of the animal body has not 
been determined, but it has been observed that infection 
will persist in buildings that have not been disinfected 
for several months. Some outbreaks of this disease 
have been apparently traced to contaminated hay, that 
had not been in contact with diseased animals for three 
months or more. Thus infection mav be obtained from 



INFECTIOUS DISEASES 231 

food, infected premises, hides and in the various animal 

serums. 

In the 1914 outbreak in the United States several 
centers of infection were undoubtedly established through 
the use of anti-hog cholera serum that had been made 
from infected hogs. This latter source is of considerable 
importance and should entail careful inspection upon the 
part of the government employes to prevent a distri- 
bution of the disease by this means. 

The usual channel of entrance of infection is through 
the abrasion of the buccal mucous membrane, but in 
hogs the infection is more frequently affected through 
abrasion of the skin in an interdigital space or around the 
superior part of the hoof. Such abrasions are no doubt 
of very common occurrence as they can easily be produced 
by stubs, sticks and splinters which are very common, in 
the pens where hogs are maintained. Infection can also 
be introduced upon food stuff, especially by milk from 
affected cows and thus gain entrance to the lesions to 
abrasions in the mouth, and as before stated infection 
may be introduced in serum. Some authorities are of 
the opinion that the disease may be carried from farm 
to farm by birds and other carrion animals and thus an 
absolute quarantine should be maintained on all infected 
premises. 

Lesions. — Foot-and-mouth disease assumes two 
forms, benign and mahgnant. As a rule hogs are not 
as seriously affected with this disease as are cattle, a 
subacute or benign form being most prevalent in these 
animals. The principal manifestation of this disease 
consists of vesicles which develop around the coronary 
band and in the interdigital spaces. One or more feet 
may be involved and these vesicles vary in size from a 
grain of wheat to a pea, and are usually of short duration. 
The surface of the epithelium ruptures and later des- 
quamates, leaving a denuded surface. The surrounded 
surface becomes tumefied and hypersensitive. Similar 
lesions may also be found on the skin of the snout and 
less frequently upon the buccal mucous membrane. If 



232 SWINE DISEASES 

the animals are maintained in clean quarters the simple 
uncomplicated lesions will heal in from ten days to three 
weeks. If the animals are maintained in muddy, filthy 
pens secondary infections frequently arise and the hoof 
may slough and the animals die of septic infection. Very 
rarely a general vesiculo-papular eruption may occur on 
large areas of the skin. 

Symptoms. — The most pronounced symptoms of 
foot-and-mouth disease in hogs consist in lameness; the 
principal lesions being found on the feet. The animals 
have a disinclination to move and because of the soreness 
tend to assume a decubital position. If the animals are 
forced to move they will probably walk upon their toes. 
The lesions in various stages of progress may be observed 
at this time by inspection. If the disease is of a virulent 
type there will be systemic disturbances consisting of rise 
of temperature, inappetence, listlessness or dullness. If 
the buccal mucous membrane is involved, there will be 
more or less of salivation and disinclination to eat. 

Course and Prognosis. — ^This disease usually runs 
its course in from one to three weeks, although it may 
progress for a longer period. The disease is ordinarily 
not fatal if uncomplicated in the hogs, although the 
financial value of the animals is considerably depreciated 
because of the fact that they rapidly emaciate. 

Treatment. — Thus far no treatment has been found 
that will curtail the course of the disease. Animals that 
have had the disease possess an immunity for a short 
time, probably not longer than six months or a year. 
The disease is of such a destructive nature in so far as 
the value of the animals is concerned, that it has always 
been considered advisable to destroy the animals and dis- 
infect the premises along with the proper disposal of the 
carcasses to insure destruction of all available virus. 

Because of the extent of the 1914 outbreak in the 
United States, it is possible that new centers of the disease 
may make its appearance at almost any time and veteri- 
narians should familiarize themselves with this disease. 



INDEX 



Actinomycosis of the skin 

153 

Actinomycosis sequel to 

castration 123 

Albuminuria 108 

Amyloid changes in the 

liver 58 

Anemia 161 

Anemia of the stomach ... 22 
Ascaridiasis of the liver. . 67 

Ascaris suum 47 

Ascites 71 

Atelectasis 84 

Bacillus coli communis . . . 178 
Bacillus necrophorus 

10, 185, 208 

Bacillus of koch 218 

Bacillus suipestifer 171 

Bacillus suisepticus 204 

Belladonna poisoning 41 

Bladder, calculi in 114 

Bladder, dilatation of . . . .113 
Bladder, malformations of 

112 

Bladder, tumors of 116 

Blood 161 

Blood vessels 160 

Botryomyces sequel to 

Castration 122 

Bronchial tubes 80 

Bronchial tubes, stenosis 

of 80 

Bronchitis 81 

Bronchitis, verminous .... 82 
Bulbo-urethral glands. . . .117 

Calculi, cystis 114 

Calculi, renal 102 

Campsomyia macell aria 

123, 153 

Castration, actinomycosis 

sequel to 123 

Castration, botryomyces 

sequel to 122 

Castration, hemorrhage 

from 119 



Castration, infection se- 
quel to 120 

Castration, parasite infes- 
tation 123 

Castration, sequels to. . . .119 
Catarrh, infectious nasal. 77 
Caustic soda poisoning. . . 39 
Caustic potash poisoning. 39 

Cerebral hyperemia 167 

Cheilitis 9 

Cholelithiasis 59 

Chorea 166 

Circulatory organs 159 

Cirrhosis-sclerosis 64 

Cloudy swelling of the 

liver 57 

Coccidiosis of the liver. . . 66 

Cocklebur poisoning 40 

Congestion of the kidneys 

102 

Cotton-seed meal poison- 
ing 44 

Cowper's glands 117 

Cryptogamic poisoning. . . 43 
Cysticercosis of the liver.. 70 
Cysticercosis of the mus- 
cles 144 

Cysticercus cellulosae 

167, 144 

Cystitis 115 

Cystitis, catarrhal 115 

Cystitis, purulent 115 

Cysts, dontigerous 127 

Cysts, dermoid 127 

Cysts, ovarian 126 

Delirium 163 

Demodex f olliculorum .... 157 

Dermatitis granulosa 152 

Dermatitis, necrotic 216 

Diaphragm, spasms of. . .228 
Diarrhea in sucklings .... 45 
Digestive system, the .... 9 
Dilatation, acute gastric. 27 
Dilatation, chronic gas- 
tric 28 

Dilatation of the bladder. 113 



234 



INDEX 



Dilatation of the esoph- 
agus 18 

Dilatation of the intes- 
tines 34 

Dilatation of the stomach 27 

Distomatosis 67 

Echinococcosis of the liver 69 

Eclampsia dentition 166 

Eczema 151 

Edema of the lungs 85 

Emesis 22 

Emphysema of the intes- 
tines 34 

Emphysema of the lungs. 85 

Endocarditis 160 

Enteritis 35 

Enteritis, necrotic 211 

Enteritis, acute catarrhal. 35 
Enteritis, chronic catar- 
rhal 36 

Enteritis, croupous and 

diptheritic 37 

Enteritis, toxic 38 

Enterorrhagia 31 

Epididymitis 118 

Epilepsy 165 

Epistaxis 75 

Erythema 149 

Esophagitis 20 

Esophagostoma dentatum 49 
Esophagus, dilatation of.. 18 
Esophagus, malformations 

of 17 

Esophagus, perforation of 19 
Esophagus, stenosis of... 18 
Esophagus, tumors of . . . . 20 

Fallopian tubes 127 

Fatty changes in the 

heart 159 

Fatty changes in the liver 57 
Fatty changes of the kid- 
neys 101 

Fatty degeneration of 

muscle 136 

Feet, sore 135 

Female reproductive or- 
gans 125 

Fleas infestation 154 

Foot and mouth disease . . 230 
Foreign bodies in the liver 54 
Foreign bodies in the 

stomach 21 

Freezing 150 

Gall-stones 59 



Garbage poisoning 42 

Gastritis 24 

Gastritis, catarrhal 24 

Gastritis, chronic 27 

Gastritis, croupous 25 

Gastritis, phlegmonous ... 26 

Gastritis, toxic 38 

Gastro-enteritis, toxic. ... 38 
Gigantorhynchus hirudin- 

aceus 52 

Glossitis 11 

Glycogenic infiltration of 

the liver 58 

Heart, fatty changes in. .159 
Heart, hemorrhage of . . . .159 

Heart, parasites of 160 

Heart, tumors of 160 

Heart stroke 164 

Hematemesis 23 

Hematuria 112 

Hemorrhage after castra- 
tion 119 

Hemorrhage of the heart. 159 
Hemorrhage of the intes- 
tines 31 

Hemorrhage of the kid- 
neys 100 

Hemorrhage of the lungs 86 
Hemorrhage of the ovary. 125 
Hemorrhage of the skin. .150 
Hemorrhage of the stom- 
ach 23 

Hemorrhage, uterine 128 

Hemothorax 95 

Hemotopinus suis 154 

Hepatitis 61 

Hepatitis, acute intersti- 
tial 63 

Hepatitis, acute paren- 

chynatous 62 

Hepatitis, chronic intersti- 
tial 64 

Hepatitis, necrotic 213 

Hepatitis, suppurative .... 62 

Hog cholera 169 

Hog cholera, interstate 

shipment of 190 

Hydronephrosis 99 

Hydrothorax 94 

Hyperemia, cerebral 167 

Hyperemia, hepatic active 61 
Hyperemia, hepatic pas- 
sive 60 

Hypermia, hepatic portal 61 



INDEX 



235 



Hyperemia of the liver. . . 60 
Hyperemia of the stom- 
ach 24 

Hypertrophy of the 

spleen 162 

Icterus 56 

Infection sequel to castra- 
tion 120 

Infectious diseases 169 

Injuries to the peritoneum 71 
Injuries to the uterus .... 127 
Intestines, dilatation of . . 34 
Intestines, emphysema of 34 
Intestines, hemorrhage of 31 
Intestines, malformations 

of 31 

Intestines, obstruction of. 33 
Intestines, parasites of . . . 46 

Intestines, tumors of 53 

Kidneys 99 

Kidneys, calculi in 102 

Kidneys, congestion of... 102 
Kidneys, fatty changes 

of 101 

Kidneys, hemorrhage of. .100 
Kidneys, malformations of 99 
Kidneys, parasites of.... 110 

Kidneys, tumors of 110 

Laryngitis 79 

Larynx, tumors of 79 

Leukemia 161 

Lightning stroke 165 

Lips, malformations of . . . 9 

Lips, tumors of 11 

Liver 54 

Liver, amyloid changes in 58 

Liver, ascaridiasis of 67 

Liver, cloudy swelling of 57 

Liver, coccidiosis of 66 

Liver, cysticercosis of . . . . 70 
Liver, distomatosis of . . . . 67 
Liver, echinococcosis of . . 69 
Liver, fatty changes in . . . 57 
Liver, foreign bodies in . . 54 
Liver, glycogenic infiltra- 
tion of 58 

Liver, malformations of . . 54 

Liver, parasites of 66 

Liver, rupture of 55 

Liver, stephanurosis of . . . 66 

Liver, tumors of 65 

Locomotion, organs of... 135 

Lousiness 154 

Lungs, edema of 85 



Lungs, emphysema of 85 

Lungs, hemorrhage of . . . 86 

Lungs, parasites of 94 

Lungs, tumors of 94 

Male generative organs.. 117 
Malformations of the 

bladder 112 

Malformations of the 

esophagus 17 

Malformations of the in- 
testines 31 

Malformations of the kid- 
neys 99 

Malformations of the lips 9 
Malformations of the liver 54 
Malformations of the 

ovary 125 

Malformations of the 

stomach 21 

Malformations of the tra- 
chea 80 

Malformations of the 

ureters 112 

Malformations of the 

uterus 127 

Mammary glands 130 

Mammary glands, tumors 

of 133 

Mammitis 130 

Mammitis, actinomycotic . 132 
Mammitis, botryomycotic . 131 
Mammitis, tuberculous ... 132 

Mange 155 

Mange, demodetic 157 

Mange, sarcoptic 155 

Measles, pork 144 

Metritis T ... 128 

Metritis, purulent 128 

Metritis, septic 128 

Mold poisoning 43 

Mouth 12 

Muscles, cysticercosis of. .144 
Muscles, fatty degenera- 
tion of 136 

Muscles, trichinosis of... 142 

Muscles, tumors of 147 

Nasal catarrh 77 

Navel ill 226 

Necrobacillosis 208 

Necrobacillosis of the in- 
testines 211 

Necrobacillosis of the 
liver 213 



236 



INDEX 



Necrobacillosis of the 

lungs 213 

Necrobacillosis of the 

nose 212 

Necrobacillosis of the pre- 
puce 214 

Necrobacillosis of the 

skin 153, 216 

Necrobacillosis of the 

spleen 214 

Necrobacillosis of the 

stomach 210 

Necrobacillosis of the 

vagina 214 

Necrobacillosis of the 

vulva 214 

Necrobacillosis, unu s u a 1 

forms of 216 

Necrosis of the spleen. . . .161 

Nephritis 103 

Nephritis, acute intersti- 
tial 105 

Nephritis, acute parenchy- 
matous 103 

Nephritis, chronic 106 

Nephritis, chronic intersti- 
tial 106 

Nephritis, purulent 105 

Nervous system, parasites 

of 167 

Nervous system, the 163 

Nose 75 

Nose, bleeding 75 

Nose, tumors of 78 

Omphalophlebitis 226 

Oophoritis 125 

Orchitis . 118 

Ornithodorus megnini .... 158 

Osteomalacia 140 

Osteomyelitis, purulent. . .141 

Ovarian cysts 126 

Ovary, hemorrhage of . . . 125 
Ovary, malformations of. 125 

Ovary, tumors of 127 

Pancreas 70 

Para-cholera 171 

Paralysis of the pharynx 17 
Parasites, Ascaris suum 

33, 47 

Parasites, Camps o m y i a 

macellaria 123, 153 

Parasites, Cvsticercus cel- 
lulosae ...' 167, 144 



Parasites, Demodex folli- 

culorum 157 

Parasites, Esophagostoma 

dentatum 49 

Parasites following cas- 
tration 123 

Parasites, Gigantorhyn- 

chus hirudinaceus. .31, 52 
Parasites, Hemotop 1 n u s 

suis 154 

Parasites of the heart. . . .160 
Parasites of the intestines 46 
Parasites of the kidneys. .110 
Parasites of the liver. . . . 6Q 
Parasites of the lungs ... 94 
Parasites of the nervous 

system 167 

Parasites of the perito- 
neum 73 

Parasites of the skin.... 153 
Parasites of the stomach . . 30 
Parasites of the tongue . . 12 
Parasites, Ornothod o r u s 

megnini 158 

Parasites, Sarc o c y s t i s 

mierscheri 147 

Parasites, Taenia margin- 

ata 70 

Parasites, Taenia solium. .144 
Parasites, Trichinella spi- 
ralis 52 

Parasites, Trichocephalus 

crenatus 50 

Parotiditis 15 

Penis 124 

Perforation of the esoph- 
agus 19 

Peritoneum 71 

Peritoneum, injuries to . . . 71 
Peritoneum, parasites of.. 73 
Peritoneum, tumors of . . . 73 

Peritonitis 72 

Pharyngitis 16 

Pharynx 16 

Pharynx, paralysis of . . . . 17 

Pharynx, tumors of 17 

Phosphorous poisoning... 40 

Phthiriasis 154 

Pericarditis 159 

Pleura 94 

Pleura, tumors of 98 

Pleurisy 96 

Pleurisy, acute 96 

Pleurisy, chronic 97 



INDEX 



237 



Pneumonia 87 

Pneumonia, necrotic 213 

Pneumonia, catarrhal 88 

Pneumonia, chronic inter- 
stitial 93 

Pneumonia, croupous 89 

Pneumonia, gangrenous or 

septic 91 

Pneumonia, purulent 90 

Pneumonia, verminous... 82 

Pneumothorax 96 

Poisoning, belladonna 41 

Poisoning, caustic potash. 39 
Poisoning, caustic, soda . . 39 

Poisoning, cocklebur 40 

Poisoning, cotton-seed 

meal 44 

Poisoning, cryptogamic ... 43 

Poisoning, garbage 42 

Poisoning, mold 43 

Poisoning, phosphorous ... 40 

Poisoning, ptomain . 43 

Poisoning, sodium chlorid 38 
Poisoning, Xanthium can- 

adense 40 

Preputial necrosis 214 

Prostate gland 117 

Ptomain poisoning 43 

Pyelonephritis 108 

Pyemic arthritis 226 

Rabies 229 

Rachitis 138 

Respiratory system, the . . 75 
Rheumatism, articular. ...137 
Rheumatism, muscular. . .136 

Rhinitis 76 

Rhinitis, necrotic 212 

Rickets 138 

Ringworm infestation. . . .158 

Rupture of the liver. ..... 55 

Sarcocystis mierscheri .... 147 

Sarcosporidiosis 146 

Schistosis labii 9 

Scours in sucklings 45 

Scrotal hernia 123 

Scurvy 15 

Serum production 199 

Skin, actinomycosis of... 153 

Skin, freezing of 150 

Skin, hemorrhage of 150 

Skin, necrobacillosis of. . .153 

Skin, parasites of 153 

Skin, the 149 

Skin, tumors of 15o 



Sodium chlorid poisoning. 38 

Spirochaeta suis 172, 178 

Spleen 161 

Spleen, hypertrophy of.. 162 

Spleen, necrosis of 161 

Spleen, tumors of 162 

Spleenitis, necrotic 214 

Stenosis of the bronchial 

tubes 80 

Stenosis of the esophagus 18 
Stenosis of the trachea ... 80 
Stephanurosis of the liver 66 

Stomach, anemia of 22 

Stomach, dilatation of . . . 27 
Stomach, foreign bodies in 21 
Stomach, hemorrhage of.. 23 
Stomach, hyperemia of . . . 24 
Stomach, malf ormati o n s 

of 21 

Stomach, parasites of 30 

Stomach, tumors of 29 

Stomach, ulcers of 23 

Stomatitis 13 

Stomatitis, necrotic 210 

Stricture of the urethra. .116 

Sunburn 149 

Sunstroke 164 

Swine plague 204 

Taenia marginata 70 

Taenia solium 144 

Testicles H^ 

Testicles, tumors of 119 

Thread worm infestation . 158 

Thumps 228 

Tick infestation 158 

Tongue H 

Tongue, parasites of 12 

Tongue, tumors of 12 

Tonsilitis 15 

Trachea, malformations of 80 

Trachea, stenosis of 80 

Trachea, tumors of 80 

Tracheitis 80 

Trichinella spiralis 52 

Trichinosis 142 

Trichocephalus crenatus . . 50 

Tubercle bacillus 218 

Tuberculosis 217 

Tumors of the bladder. . .116 
Tumors of the esophagus 20 

Tumors of the heart 160 

Tumors of the intestines . . 53 
Tumors of the kidneys. . .110 
Tumors of the larynx 79 



238 



INDEX 



Tumors of the lips 11 

Tumors of the liver 65 

Tumors of the lungs 94 

Tumors of the mammary- 
glands 133 

Tumors of the muscles . . . 147 

Tumors of the nose 78 

Tumors of the ovary 127 

Tumors of the peritoneum 73 
Tumors of the pharynx. . 17 
Tumors of the pleura .... 98 

Tumors of the skin 153 

Tumors of the spleen .... 162 
Tumors of the stomach. . 29 
Tumors of the testicles. .119 
Tumors of the tongue .... 12 
Tumors of the trachea. . . 80 
Tumors of the uterus .... 129 
Ulces of the stomach .... 23 
Ulcers, peptic 23 



Uremia 109 

Ureters, malforma t i o n s 

of 112 

Urethra 116 

Urethra, stricture of 116 

Urethritis 117 

Uro-genital system, the . . 99 

Urticaria 151 

Uterine hemorrhage 128 

Uterus, injuries to 127 

Uterus, malformations of .127 

Uterus, tumors of 129 

Vagina 129 

Vaginitis, necrotic 214 

Viciousness 163 

Vomition 22 

Vulva 130 

Vulvitis, necrotic 214 

Xanthium canadense 40 



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